01The Language of Music
A painter hangs his or her finished pictures on a wall, and everyone can see it.A composer writes a work, but no one can hear it until it is performed.Profeional singers and players have great responsibilities, for the composer is utterly dependent on them.A student of music needs as long and as arduous a training to become a performer as a medical student needs to become a doctor.Most training is concerned with technique, for musicians have to have the muscular proficiency of an athlete ora ballet dancer.Singers practice breathing every day, as their vocal chords would be inadequate without controlled muscular support.String players practice moving the fingers of the left hand up and down, while drawing the bow to and fro with the right arm—two entirely different movements.
Singers and instruments have to be able to get every note perfectly in tune.Pianists are spared this particular anxiety,for the notes are already there, waiting for them, and it is the piano tuner’s responsibility to tune the instrument for them.But they have their own difficulties; the hammers that hit the string have to be coaxed not to sound like percuion, and each overlapping tone has to sound clear.
This problem of getting clear texture is one that confronts student conductors: they have to learn to know every note of the music and how it should sound, and they have to aim at controlling these sound with fanatical but selfle authority.
Technique is of no use unle it is combined with musical knowledge and understanding.Great artists are those who are so thoroughly at home in the language of music that they can enjoy performing works written in any century.
02 Schooling and Education
It is commonly believed in United States that school is where people go to get an education.Neverthele, it has been said that today children interrupt their education to go to school.The distinction between schooling and education implied by this remark is important.
Education is much more open-ended and all-inclusive than schooling.Education knows no bounds.It can take place anywhere, whether in the shower or in the job, whether in a kitchen or on a tractor.It includes both the formal learning that takes place in schools and the whole universe of informal learning.The agents of education can range from a revered grandparent to the people debating politics on the radio, from a child to a distinguished scientist.Whereas schooling has a certain predictability, education quite often produces surprises.A chance conversation with a stranger may lead a person to discover how little is known of other religions.People are engaged in education from infancy on.Education, then, is a very broad, inclusive term.It is a lifelong proce, a proce that starts long before the start of school, and one that should be an integral part of one’s entire life. Schooling, on the other hand, is a specific,formalized proce, whose general pattern varies little from one setting to the next.Throughout a country, children arrive at school at approximately the same time, take aigned seats, are taught by an adult, use similar textbooks, do homework, take exams, and so on.The slices of reality that are to be learned,whether they are the alphabet or an understanding of the working of government,have usually been limited by the boundaries of the subject being taught.For example, high school students know that there not likely to find out in their claes the truth about political problems in their communities or what the newest filmmakers are experimenting with.There are definite conditions surrounding the formalized proce of schooling.
03 The Definition of “Price”
Prices determine how resources are to be used.They are also the means by which products and services that are in limited supply are rationed among buyers.The price system of the United States is a complex network composed of the prices of all the products bought and sold in the economy as well as those of a myriad of services, including labor, profeional,transportation, and public-utility services.The interrelationships of all these prices make up the ―system‖ of prices.The price of any particular product or service is linked to a broad, complicated system of prices in which everything seems to depend more or le upon everything else.
If one were to ask a group of randomly selected individuals to define ―price‖, many would reply that price is an amount of money paid by the buyer to the seller of a product or service or, in other words that price is the money values of a product or service as agreed upon in a market transaction.This definition is, of course, valid as far as it goes.For a complete understanding of a price in any particular transaction,much more than the amount of money involved must be known.Both the buyer and the seller should be familiar with not only the money amount, but with the amount and quality of the product or service to be exchanged, the time and place at which the exchange will take place and payment will be made, the form of money to be used, the credit terms and discounts that apply to the transaction, guarantees on the product or service, delivery terms, return privileges, and other factors.In other words, both buyer and seller should be fully aware of all the factors that comprise the total ―package‖ being exchanged for the asked-for amount of money in order that they may evaluate a given price.
04 Electricity
The modern age is an age of electricity.People are so used to electric lights, radio, televisions, and telephones that it is hard to imagine what life would be like without them.When there is a power failure, people grope about in flickering candlelight, cars hesitate in the streets because there are no traffic lights to guide them, and food spoils in silent refrigerators.
Yet, people began to understand how electricity works only a little more than two centuries ago.Nature has apparently been experimenting in this field for million of years.Scientists are discovering more and more that the living world may hold many interesting secrets of electricity that could benefit humanity.
All living cell send out tiny pulses of electricity.As the heart beats, it sends out pulses of record; they form an electrocardiogram, which a doctor can study to determine how well the heart is working.The brain, too, sends out brain waves of electricity, which can be recorded in an electroencephalogram.The electric currents generated by most living cells are extremely small – often so small that sensitive instruments are needed to record them.But in some animals, certain muscle cells have become so specialized as electrical generators that they do not work as muscle cells at all.When large numbers of these cell are linked together, the effects can be astonishing.
The electric eel is an amazing storage battery.It can seed a jolt of as much as eight hundred volts of electricity through the water in which it live.( An electric house current is only one hundred twenty volts.) As many as four-fifths of all the cells in the electric eel’s body are specialized for generating electricity, and the strength of the shock it can deliver corresponds roughly to length of its body.
05 The Beginning of Drama
There are many theories about the beginning of drama in ancient Greece.The on most widely accepted today is based on the aumption that drama evolved from ritual.The argument for this view goes as follows.In the beginning, human beings viewed the natural forces of the world-even the seasonal changes-as unpredictable, and they sought through various means to control these unknown and feared powers.Those measures which appeared to bring the desired results were then retained and repeated until they hardened into fixed rituals.Eventually stories arose which explained or veiled the mysteries of the rites.As time paed some rituals were abandoned,but the stories, later called myths, persisted and provided material for art and drama.
Those who believe that drama evolved out of ritual also argue that those rites contained the seed of theater because music,dance, masks, and costumes were almost always used, Furthermore, a suitable site had to be provided for performances and when the entire community did not participate, a clear division was usually made between the \"acting area\" and the \"auditorium.\" In addition, there were performers,and, since considerable importance was attached to avoiding mistakes in the enactment of rites, religious leaders usually aumed that task.Wearing masks and costumes, they often impersonated other people, animals, or supernatural beings, and mimed the desired effect-succe in hunt or battle, the coming rain, the revival of the Sun-as an actor might.Eventually such dramaticrepresentations were separated from religious activities.
Another theory traces the theater\'s originfrom the human interest in storytelling.According to this vies tales (aboutthe hunt, war, or other feats) are gradually elaborated, at first through theuse of impersonation, action, and dialogue by a narrator and then through theaumption of each of the roles by a different person.A closely related theorytraces theater to those dances that are primarily rhythmical and gymnastic orthat are imitations of animal movements and sounds.
06 Television
Television-----the most pervasive andpersuasive of modern technologies, marked by rapid change and growth-is movinginto a new era, an era of extraordinary sophistication and versatility, whichpromises to reshape our lives and our world.It is an electronic revolution ofsorts, made poible by the marriage of television and computer technologies.
The word \"television\", derivedfrom its Greek (tele: distant) and Latin (visio: sight) roots, can literally beinterpreted as sight from a distance.Very simply put, it works in this way:through a sophisticated system of electronics, television provides thecapability of converting an image (focused on a special photoconductive platewithin a camera) into electronic impulses, which can be sent through a wire orcable.These impulses, when fed into a receiver (television set), can then beelectronically reconstituted into that same image.
Television is more than just an electronicsystem, however.It is a means of expreion, as well as a vehicle forcommunication, and as such becomes a powerful tool for reaching other humanbeings.
The field of television can be divided intotwo categories determined by its means of transmiion.First, there isbroadcast television, which reaches the maes through broad-based airwave transmiionof television signals.Second, there is nonbroadcast television, which providesfor the needs of individuals or specific interest groups through controlledtransmiion techniques.
Traditionally, television has been a mediumof the maes.We are most familiar with broadcast television because it hasbeen with us for about thirty-seven years in a form similar to what existstoday.During those years, it has been controlled, for the most part, by thebroadcast networks, ABC, NBC, and CBS, who have been the major purveyors ofnews, information, and entertainment.These giants of broadcasting haveactually shaped not only television but our perception of it as well.We havecome to look upon the picture tube as a source of entertainment, placing ourrole in this dynamic medium as the paive viewer.
07 Andrew Carnegie
Andrew Carnegie, known as the King of Steel,built the steel industry in the United States, and , in the proce, became oneof the wealthiest men in America.His succe resulted in part from his abilityto sell the product and in part from his policy of expanding during periods ofeconomic decline, when most of his competitors were reducing their investments.
Carnegie believed that individuals shouldprogre through hard work, but he also felt strongly that the wealthy shoulduse their fortunes for the benefit of society.He opposed charity, preferringinstead to provide educational opportunities that would allow others to helpthemselves.\"He who dies rich, dies disgraced,\" he often said.
Among his more noteworthy contributions tosociety are those that bear his name, including the Carnegie Institute ofPittsburgh, which has a library, a museum of fine arts, and a museum ofnational history.He also founded a school of technology that is now part ofCarnegie-Mellon University.Other philanthrophic gifts are the CarnegieEndowment for International Peace to promote understanding between nations, theCarnegie Institute of Washington to fund scientific research, and Carnegie Hallto provide a center for the arts.
Few Americans have been left untouched byAndrew Carnegie\'s generosity.His contributions of more than five milliondollars established 2,500 libraries in small communities throughout the countryand formed the nucleus of the public library system that we all enjoy today.
08 American Revolution
The American Revolution was not a sudden andviolent overturning of the political and social framework, such as lateroccurred in France and Ruia, when both were already independent nations.Significant changes were ushered in, but they were not breathtaking.Whathappened was accelerated evolution rather than outright revolution.During theconflict itself people went on working and praying, marrying and playing.Mostof them were not seriously disturbed by the actual fighting, and many of themore isolated communities scarcely knew that a war was on.
America\'s War of Independence heralded thebirth of three modern nations.One was Canada, which received its first largeinflux of English-speaking population from the thousands of loyalists who fledthere from the United States.Another was Australia, which became a penalcolony now that America was no longer available for prisoners and debtors.Thethird newcomer-the United States-based itself squarely on republicanprinciples.
Yet even the political overturn was not sorevolutionary as one might suppose.In some states, notably Connecticut andRhode Island, the war largely ratified a colonial self-rule already existing.British officials, everywhere ousted, were replaced by a home-grown governingcla, which promptly sought a local substitute for king and Parliament.
09 Suburbanization
If by \"suburb\" is meant an urbanmargin that grows more rapidly than its already developed interior, the proceof suburbanization began during the emergence of the industrial city in thesecond quarter of the nineteenth century.Before that period the city was asmall highly compact cluster in which people moved about on foot and goods wereconveyed by horse and cart.But the early factories built in the 1840\'s werelocated along waterways and near railheads at the edges of cities, and housingwas needed for the thousands of people drawn by the prospect of employment.Intime, the factories were surrounded by proliferating mill towns of apartmentsand row houses that abutted the older, main cities.As a defense against thisencroachment and to enlarge their tax bases, the cities appropriated theirindustrial neighbors.In 1854, for example, the city of Philadelphia annexedmost of Philadelphia County.Similar municipal maneuvers took place in Chicagoand in New York.Indeed, most great cities of the United States achieved suchstatus only by incorporating the communities along their borders.
With the acceleration of industrial growth came acute urban crowding andaccompanying social stre-conditions that began to approach disastrousproportions when, in 1888, the first commercially succeful electric tractionline was developed.Within a few years the horse-drawn trolleys were retiredand electric streetcar networks cricroed and connected every major urbanarea, fostering a wave of suburbanization that transformed the compactindustrial city into a dispersed metropolis.This first phase of ma-scalesuburbanization was reinforced by the simultaneous emergence of the urbanMiddle Cla, whose desires for homeownership in neighborhoods far from theaging inner city were satisfied by the developers of single-family housingtracts.
10 Types of Speech
Standard usage includes those words andexpreions understood, used, and accepted by a majority of the speakers of alanguage in any situation regardle of the level of formality.As such, thesewords and expreions are well defined and listed in standard dictionaries.Colloquialisms, on the other hand, are familiar words and idioms that areunderstood by almost all speakers of a language and used in informal speech orwriting, but not considered appropriate for more formal situations.Almost allidiomatic expreions are colloquial language.Slang, however, refers to wordsand expreions understood by a large number of speakers but not accepted asgood, formal usage by the majority.Colloquial expreions and even slang maybe found in standard dictionaries but will be so identified.Both colloquialusage and slang are more common in speech than in writing.
Colloquial speech often paes into standardspeech.Some slang also paes into standard speech, but other slangexpreions enjoy momentary popularity followed by obscurity.In some cases,the majority never accepts certain slang phrases but neverthele retains themin their collective memories.Every generation seems to require its own set ofwords to describe familiar objects and events.It has been pointed out by anumber of linguists that three cultural conditions are neceary for thecreation of a large body of slang expreions.First, the introduction andacceptance of new objects and situations in the society; second, a diversepopulation with a large number of subgroups; third, aociation among thesubgroups and the majority population.
Finally, it is worth noting that the terms\"standard\" \"colloquial\" and \"slang\" exist only asabstract labels for scholars who study language.Only a tiny number of thespeakers of any language will be aware that they are using colloquial or slangexpreions.Most speakers of English will, during appropriate situations,select and use all three types of expreions.11 Archaeology
Archaeology is a source of history, not justa bumble auxiliary discipline.Archaeological data are historical documents intheir own right, not mere illustrations to written texts, Just as much as anyother historian, an archaeologist studies and tries to reconstitute the procethat has created the human world in which we livespace.Withcollections expanding, with the needs and functions of museums changing, emptyspace has become a very precious commodity.
Probably nowhere in the country is this moretrue than at the Philadelphia Museum of Art, which has needed additional spacefor decades and which received its last significant facelift ten years ago.Because of the space crunch, the Art Museum has become increasingly cautious inconsidering acquisitions and donations of art, in some cases paing upopportunities to strengthen its collections.
Deacceingworks of arthas taken on new importance because of the museum\'s space problems.Andincreasingly, curators have been forced to juggle gallery space, rotating onemasterpiece into public view while another is sent to storage.
Despite the clear need for additionalgallery and storage space, however,\" the museum has no plan, no plan tobreak out of its envelope in the next fifteen years,\" according toPhiladelphia Museum of Art\'s president.
13 Skyscrapers and Environment
In the late 1960\'s, many people in NorthAmerica turned their attention to environmental problems, and newsteel-and-gla skyscrapers were widely criticized.Ecologists pointed out thata cluster of tall buildings in a city often overburdens public transportationand parking lot capacities.
Skyscrapers are also lavish consumers, andwasters, of electric power.In one recent year, the addition of 17 millionsquare feet of skyscraper office space in New York City raised the peak dailydemand for electricity by 120, 000 kilowatts-enough to supply the entire cityof Albany, New York, for a day.
Gla-walled skyscrapers can be especiallywasteful.The heat lo (or gain)through a wall of half-inch plate gla ismore than ten times that through a typical masonry wall filled with insulationboard.To leen the strain on heating and air-conditioning equipment, buildersof skyscrapers have begun to use double-glazed panels of gla, and reflectiveglaes coated with silver or gold mirror films that reduce glare as well asheat gain.However, mirror-walled skyscrapers raise the temperature of thesurrounding air and affect neighboring buildings.
Skyscrapers put a severe strain on a city\'anitation facilities, too.If fully occupied, the two World Trade Centertowers in New York City would alone generate 2.25 million gallons of raw sewageeach year-as much as a city the size of Stanford, Connecticut , which has apopulation of more than 109, 000.
14 A Rare Foil Record
The preservation of embryos and juveniles isa rate occurrence in the foil record.The tiny, delicate skeletons areusually scattered by scavengers or destroyed by weathering before they can befoilized.Ichthyosaurs had a higher chance of being preserved than didterrestrial creatures because, as marine animals, they tended to live inenvironments le subject to erosion.Still, their foilization required asuite of factors: a slow rate of decay of soft tiues, little scavenging byother animals, a lack of swift currents and waves to jumble and carry awaysmall bones, and fairly rapid burial.Given these factors, some areas have becomea treasury of well-preserved ichthyosaur foils.
The deposits at Holzmaden, Germany, presentan interesting case for analysis.The ichthyosaur remains are found in black,bituminous marine shales deposited about 190 million years ago.Over the years,thousands of specimens of marine reptiles, fish and invertebrates have beenrecovered from these rocks.The quality of preservation is outstanding, butwhat is even more impreive is the number of ichthyosaur foils containingpreserved embryos.Ichthyosaurs with embryos have been reported from 6different levels of the shale in a small area around Holzmaden, suggesting thata specific site was used by large numbers of ichthyosaurs repeatedly over time.The embryos are quite advanced in their physical development; their paddles,for example, are already well formed.One specimen is even preserved in thebirth canal.In addition, the shale contains the remains of many newborns thatare between 20 and 30 inches long.
Why are there so many pregnant females andyoung at Holzmaden when they are so rare elsewhere? The quality of preservationis almost unmatched and quarry operations have been carried out carefully withan awarene of the value of the foils.But these factors do not account forthe interesting question of how there came to be such a concentration ofpregnant ichthyosaurs in a particular place very close to their time of givingbirth.
15 The Nobel Academy
For the last 82years, Sweden\'s Nobel Academyhas decided who will receive the Nobel Prize in Literature, thereby determiningwho will be elevated from the great and the near great to the immortal.Buttoday the Academy is coming under heavy criticism both from the without andfrom within.Critics contend that the selection of the winners often has leto do with true writing ability than with the peculiar internal politics of theAcademy and of Sweden itself.According to Ingmar Bjorksten , the culturaleditor for one of the country\'s two major newspapers, the prize continues torepresent \"what people call a very Swedish exercise: reflecting Swedishtastes.\"
The Academy has defended itself against suchcharges of provincialism in its selection by aerting that its physicaldistance from the great literary capitals of the world actually serves toprotect the Academy from outside influences.This may well be true, but criticsrespond that this very distance may also be responsible for the Academy\'sinability to perceive accurately authentic trends in the literary world.
Regardle of concerns over the selectionproce, however, it seems that the prize will continue to survive both as anindicator of the literature that we most highly praise, and as an elusive goalthat writers seek.If for no other reason, the prize will continue to be desirablefor the financial rewards that accompany it; not only is the cash prize itselfconsiderable, but it also dramatically increases sales of an author\'s books.
16.the war betweenBritain and France
In the late eighteenth century, battles raged in almostevery corner of Europe, as well as in the Middle East, south Africa ,the WestIndies, and Latin America.In reality, however, there was only one major warduring this time, the war between Britain and France.All other battles wereancillary to this larger conflict, and were often at least partially related toits antagonist’ goals and strategies.France sought total domination of Europe.this goal was obstructed by British independence and Britain’s effortsthroughout the continent to thwart Napoleon; through treaties.Britain builtcoalitions (not diimilar in concept to today’s NATO) guaranteeing Britishparticipation in all major European conflicts.These two antagonists werepoorly matched, insofar as they had very unequal strengths; France waspredominant on land, Britain at sea.The French knew that, short of defeatingthe British navy, their only hope of victory was to close all the ports ofEurope to British ships.Accordingly, France set out to overcome Britain byextending its military domination from Moscow t Lisbon, from Jutland toCalabria.All of this entailed tremendous risk, because France did not have themilitary resources to control this much territory and still protect itself andmaintain order at home.
French strategists calculated that a navy of 150 shipswould provide the force neceary to defeat the British navy.Such a forcewould give France a three-to-two advantage over Britain.This advantage wasdeemed neceary because of Britain’s superior sea skills and technology becauseof Britain’s superior sea skills and technology, and also because Britain wouldbe fighting a defensive war, allowing it to win with fewer forces.Napoleonnever lost substantial impediment to his control of Europe.As his force nearedthat goal, Napoleon grew increasingly impatient and began planning an immediateattack.
17.Evolution of sleep
Sleep is very ancient.In the electroencephalographicsense we share it with all the primates and almost all the other mammals andbirds: it may extend back as far as the reptiles.
There is some evidence that the two types of sleep,dreaming and dreamle, depend on the life-style of the animal, and thatpredators are statistically much more likely to dream than prey, which are inturn much more likely to experience dreamle sleep.In dream sleep, the animalis powerfully immobilized and remarkably unresponsive to external stimuli.Dreamle sleep is much shallower, and we have all witneed cats or dogscocking their ears to a sound when apparently fast asleep.The fact that deepdream sleep is rare among pray today seems clearly to be a product of naturalselection, and it makes sense that today, when sleep is highly evolved, thestupid animals are le frequently immobilized by deep sleep than the smart ones.But why should they sleep deeply at all? Why should a state of such deepimmobilization ever have evolved?
Perhaps one useful hint about the original function ofsleep is to be found in the fact that dolphins and whales and aquatic mammalsin genera seem to sleep very little.There is, by and large, no place to hidein the ocean.Could it be that, rather than increasing an animal’svulnerability, the University of Florida and Ray Meddis of London Universityhave suggested this to be the case.It is conceivable that animals who are toostupid to be quite on their own initiative are, during periods of high risk,immobilized by the implacable arm of sleep.The point seems particularly clearfor the young of predatory animals.This is an interesting notion and probablyat least partly true.
18.Modern American Universities胖胖：）
Before the 1850’s, the United States had anumber of small colleges, most of them dating from colonial days.They weresmall, church connected institutions whose primary concern was to shape themoral character of their students.
Throughout Europe, institutions of higherlearning had developed, bearing the ancient name of university.In Germanuniversity was concerned primarily with creating and spreading knowledge, notmorals.Between mid-century and the end of the 1800’s, more than nine thousandyoung Americans, diatisfied with their training at home, went to Germany foradvanced study.Some of them return to become presidents of venerablecolleges-----Harvard, Yale, Columbia---and transform them into modernuniversities.The new presidents broke all ties with the churches and broughtin a new kind of faculty.Profeors were hired for their knowledge of asubject, not because they were of the proper faith and had a strong arm fordisciplining students.The new principle was that a university was to createknowledge as well as pa it on, and this called for a faculty composed ofteacher-scholars.Drilling and learning by rote were replaced by the Germanmethod of lecturing, in which the profeor’s own research was presented incla.Graduate training leading to the Ph.D., an ancient German degreesignifying the highest level of advanced scholarly attainment, was introduced.With the establishment of the seminar system, graduate student learned toquestion, analyze, and conduct their own research.
At the same time, the new university greatlyexpanded in size and course offerings, breaking completely out of the old,constricted curriculum of mathematics, claics, rhetoric, and music.Thepresident of Harvard pioneered the elective system, by which students were ableto choose their own course of study.The notion of major fields of studyemerged.The new goal was to make the university relevant to the real pursuitsof the world.Paying close heed to the practical needs of society, the newuniversities trained men and women to work at its tasks, with engineeringstudents being the most characteristic of the new regime.Students were alsotrained as economists, architects, agriculturalists, social welfare workers,and teachers.
19.children’s numerical skills怎么还是胖胖：）
people appear to born to compute.Thenumerical skills of children develop so early and so inexorably that it is easyto imagine an internal clock of mathematical maturity guiding their growth.Notlong after learning to walk and talk, they can set the table with impreaccuracy---one knife, one spoon, one fork, for each of the five chairs.Soonthey are capable of nothing that they have placed five knives, spoons and forkson the table and, a bit later, that this amounts to fifteen pieces ofsilverware.Having thus mastered addition, they move on to subtraction.Itseems almost reasonable to expect that if a child were secluded on a desertisland at birth and retrieved seven years later, he or she could enter a secondenter a second-grade mathematics cla without any serious problems ofintellectual adjustment.
Of course, the truth is not so simple.Thiscentury, the work of cognitive psychologists has illuminated the subtle formsof daily learning on which intellectual progre depends.Children wereobserved as they slowly grasped-----or, as the case might be, bumpedinto-----concepts that adults take for quantity is unchanged as water poursfrom a short gla into a tall thin one.Psychologists have since demonstratedthat young children, asked to count the pencils in a pile, readily report thenumber of blue or red pencils, but must be coaxed into finding the total.Suchstudies have suggested that the rudiments of mathematics are masteredgradually, and with effort.They have also suggested that the very concept ofabstract numbers------the idea of a onene,
a twone, a threene that applies to anycla of objects and is a prerequisite for doing anything more mathematicallydemanding than setting a table-----is itself far from innate
20 The Historical Significanceof American Revolution
The ways of history are so intricate and themotivations of human actions so complex that it is always hazardous to attemptto represent events covering a number of years, a multiplicity of persons, anddistant localities as the expreion of one intellectual or social movement;yet the historical proce which culminated in the ascent of Thomas Jeffersonto the presidency can be regarded as the outstanding example not only of thebirth of a new way of life but of nationalism as a new way of life.TheAmerican Revolution represents the link between the seventeenth century, inwhich modern England became conscious ofitself, and the awakening of modern Europe at the end of the eighteenthcentury.It may seem strange that the march of history should have had to crothe Atlantic Ocean, but only in theNorth American colonies could a struggle for civic liberty lead also to thefoundation of a new nation.Here, in the popular rising against a ―tyrannical‖government, the fruits were more than the securing of a freer constitution.They included the growth of a nation born in liberty by the will of the people,not from the roots of common descent, a geographic entity, or the ambitions ofking or dynasty.With the American nation, for the first time, a nation wasborn, not in the dim past of history but before the eyes of the whole world.21 The Origin of Sports
When did sport begin? If sport is, ineence, play, the claim might be made that sport is much older than humankind,for , as we all have observed, the beasts play.Dogs and cats wrestle and playball games.Fishes and birds dance.The apes have simple, pleasurable games.Frolicking infants, school children playing tag, and adult arm wrestlers aredemonstrating strong, transgenerational and tranpecies bonds with theuniverse of animals – past, present, and future.Young animals, particularly,tumble, chase, run wrestle, mock, imitate, and laugh (or so it seems) to thepoint of delighted exhaustion.Their play, and ours, appears to serve no otherpurpose than to give pleasure to the players, and apparently, to remove ustemporarily from the anguish of life in earnest.
Somephilosophers have claimed that our playfulne is the most noble part of ourbasic nature.In their generous conceptions, play harmlely and experimentallypermits us to put our creative forces, fantasy, and imagination into action.Play is release from the tedious battles against scarcity and decline which arethe inceant, and inevitable, tragedies of life.This is a grand conceptionthat excites and provokes.The holders of this view claim that the origins ofour highest accomplishments ---- liturgy, literature, and law ---- can betraced to a play impulse which, paradoxically, we see most purely enjoyed byyoung beasts and children.Our sports, in this rather happy, nonfatalistic viewof human nature, are more splendid creations of the nondatable, tranpeciesplay impulse.
22.Collectibles Collectibles have been a part of almostevery culture since ancient times.Whereas some objects have been collected fortheir usefulne, others have been selected for their aesthetic beauty alone.In the United States, the kinds of collectibles currently popular range fromtraditional objects such as stamps, coins, rare books, and art to more recentitems of interest like dolls, bottles, baseball cards, and comic books.
Interest in collectibles has increasedenormously during the past decade, in part because some collectibles havedemonstrated their value as investments.Especially during cycles of highinflation, investors try to purchase tangibles that will at least retain theircurrent market values.In general, the most traditional collectibles will besought because they have preserved their value over the years, there is anorganized auction market for them, and they are most easily sold in the eventthat cash is needed.Some examples of the most stable collectibles are oldmasters, Chinese ceramics, stamps, coins, rare books, antique jewelry, silver,porcelain, art by well-known artists, autographs, and period furniture.Otheritems of more recent interest include old photograph records, old magazines,post cards, baseball cards, art gla, dolls, claic cars, old bottles, andcomic books.These relatively new kinds of collectibles may actually appreciatefaster as short-term investments, but may not hold their value as long-terminvestments.Once a collectible has had its initial play, it appreciates at afairly steady rate, supported by an increasing number of enthusiasticcollectors competing for the limited supply of collectibles that becomeincreasingly more difficult to locate.
23 Ford
Although Henry Ford’s name is closelyaociated with the concept of ma production, he should receive equal creditfor introducing labor practices as early as 1913 that would be consideredadvanced even by today’s standards.Safety measures were improved, and the workday was reduced to eight hours, compared with the ten-or twelve-hour day commonat the time.In order to accommodate the shorter work day, the entire factorywas converted from two to three shifts.
In addition, sick leaves as well as improvedmedical care for those injured on the job were instituted.The Ford MotorCompany was one of the first factories to develop a technical school to trainspecialized skilled laborers and an English language school for immigrants.Some efforts were even made to hire the handicapped and provide jobs for formerconvicts.
The most widely acclaimed innovation was thefive-dollar-a-day minimum wage that was offered in order to recruit and retainthe best mechanics and to discourage the growth of labor unions.Ford explainedthe new wage policy in terms of efficiency and profit sharing.He alsomentioned the fact that his employees would be able to purchase the automobilesthat they produced – in effect creating a market for the product.In order toqualify for the minimum wage, an employee had to establish a decent home anddemonstrate good personal habits, including sobriety, thriftine,industriousne, and dependability.Although some criticism was directed atFord for involving himself too much in the personal lives of his employees,there can be no doubt that, at a time when immigrants were being takenadvantage of in frightful ways, Henry Ford was helping many people to establishthemselves in America.
24．Piano
The ancestry of the piano can be traced tothe early keyboard instruments of the fifteenth and sixteenth centuries --- thespinet, the dulcimer, and the virginal.In the seventeenth century the organ,the clavichord, and the harpsichord became the chief instruments of thekeyboard group, a supremacy they maintained until the piano supplanted them atthe end of the eighteenth century.The clavichord’s tone was metallic and neverpowerful; neverthele, because of the variety of tone poible to it, manycomposers found the clavichord a sympathetic instrument for intimate chambermusic.The harpsichord with its bright, vigorous tone was the favoriteinstrument for supporting the ba of the small orchestra of the period and forconcert use, but the character of the tone could not be varied save bymechanical or structural devices.
The piano was perfected in the earlyeighteenth century by a harpsichord maker in Italy (though musicologists pointout several previous instances of theinstrument).This instrument was called a piano e forte (sort and loud), toindicate its dynamic versatility; its strings were struck by a recoiling hammerwith a felt-padded head.The wires were much heavier in the earlierinstruments.A series of mechanical improvements continuing well into thenineteenth century, including the introduction of pedals to sustain tone or tosoften it, the perfection of a metal frame, and steel wire of the finestquality, finally produced an instrument capable of myriad tonal effects from themost delicate harmonies to an almost orchestral fullne of sound, from aliquid, singing tone to a sharp, percuive brilliance.
NOTE: Musical Instruments 1.Thestrings (弦乐) 1) plectrum: harp,lute, guitar, mandolin; 2) keyboard:clavichord, harpsichord, piano; 3) bow: violin,viola, cello, double ba.2.The Wood（木管）—winds : piccolo, flute, oboe, clarinet,baoon, English horn; 3.the bra（铜管）: Frenchhorn, trumpet, trombone, cornet, tuba, bugle, saxophone; 4.thepercuion（打击组）: kettledrum, ba drum, snare drum, castanet, xylophone, celesta, cymbal, tambourine.
25.Movie Music
Accustomed though we are to speaking of thefilms made before 1927 as ―silent‖, the film has never been, in the full senseof the word, silent.From the very beginning, music was regarded as anindispensable accompaniment; when the Lumiere films were shown at the firstpublic film exhibition in the United States in February 1896, they were accompaniedby piano improvisations on popular tunes.At first, the music played bore nospecial relationship to the films; an accompaniment of any kind was sufficient.Within a very short time, however, the incongruity of playing lively music to asolemn film became apparent, and film pianists began to take some care inmatching their pieces to the mood of the film.
As movie theaters grew in number andimportance, a violinist, and perhaps a cellist, would be added to the pianistin certain cases, and in the larger movie theaters small orchestras wereformed.For a number of years the selection of music for each film programrested entirely in the hands of the conductor or leader of the orchestra, andvery often the principal qualification for holding such a position was notskill or taste so much as the ownership of a large personal library of musicalpieces.Since the conductor seldom saw the films until the night before theywere to be shown(if indeed, the conductor was lucky enough to see them then), themusical arrangement was normally improvised in the greatest hurry.
To help meet this difficulty, filmdistributing companies started the practice of publishing suggestions formusical accompaniments.In 1909, for example, the Edison Company began iuingwith their films such indications of mood as ― pleasant‖, ―sad‖, ―lively‖.Thesuggestions became more explicit, and so emerged the musical cue sheetcontaining indications of mood, the titles of suitable pieces of music, andprecise directions to show where one piece led into the next.
Certain films had music especially composedfor them.The most famous of these early special scores was that composed andarranged for D.W Griffith’s film Birth of a Nation, which was released in 1915.
Note: 美国通俗音乐分类： 1．Jazz;
1) traditional jazz---- a) blues, 代表人物：Billy Holiday
b)ragtime(切分乐曲): 代表人物：Scott Joplin
c)New Orleans jazz (= Dixieland jazz) eg: Louis Armstron
d)swing
eg: Glenn Miller, Duke Ellington, etc.
e)bop (=bebop, rebop) eg: Lester Young, Charlie Parker etc.
2)modern jazz ------ a) cool jazz(=progreive jazz)高雅爵士乐。 Eg: Kenny G.
b)third-stream jazz. Eg: Charles Mingus, John Lewis.
c) main stream jazz.
d)avant-garde jazz.
e) soul jazz.Eg: Sarah Vaughn, EllaFitzgerald
f) Latin jazz.2.gospelmusic 福音音乐， 主要源于Nero spirituals.Eg.Dolly Parker, Mahalia Jackson 3.Countryand Western music.Eg.John Denver, Tammy Wynette, Kenny Rogers, etc.4.Rock music-----------a) rock and roll eg: Elvis Prestley(US) , the Beatles(UK.)
b)folk rock Eg: Bob Dylon, Michael Jackson,Mariah Carey, Bruce Springsteen, Lionel Riche etc.
c)punk rock
d)acid rock
e)rock jazz eg: M.J.McLaughlin
f) Juraic rock 5.Musicfor easy listening (i.e.light music )
26.International Busine andCro-cultural Communication
The increase in international busine andin foreign investment has created a need for executives with knowledge offoreign languages and skills in cro-cultural communication.Americans,however, have not been well trained in either area and, consequently, have notenjoyed the same level of succe in negotiation in an international arena ashave their foreign counterparts.
Negotiating is the proce of communicatingback and forth for the purpose of reaching an agreement.It involves persuasionand compromise, but in order to participate in either one, the negotiators mustunderstand the ways in which people are persuaded and how compromise is reachedwithin the culture of the negotiation.
In many international busine negotiationsabroad, Americans are perceived as wealthy and impersonal.It often appears tothe foreign negotiator that the American represents a largemulti-million-dollar corporation that can afford to pay the price withoutbargaining further.The American negotiator’s role becomes that of animpersonal purveyor of information and cash.
In studies of American negotiators abroad,several traits have been identified that may serve to confirm thitereotypical perception, while undermining the negotiator’s position.Twotraits in particular that cause cro-cultural misunderstanding are directneand impatience on the part of the American negotiator.Furthermore, Americannegotiators often insist on realizing short-term goals.Foreign negotiators, onthe other hand, may value the relationship established between negotiators andmay be willing to invest time in it for long-term benefits.In order tosolidify the relationship, they may opt for indirect interactions withoutregard for the time involved in getting to know the other negotiator.
27.Scientific Theories In science, a theory is a reasonableexplanation of observed events that are related.A theory often involves animaginary model that helps scientists picture the way an observed event couldbe produced.A good example of this is found in the kinetic molecular theory,in which gases are pictured as being made up of many small particles that arein constant motion.
A useful theory, in addition to explainingpast observations, helps to predict events that have not as yet been observed.After a theory has been publicized, scientists design experiments to test thetheory.If observations confirm the scientist’s predictions, the theory iupported.If observations do not confirm the predictions, the scientists mustsearch further.There may be a fault in the experiment, or the theory may haveto be revised or rejected.
Science involves imagination and creativethinking as well as collecting information and performing experiments.Facts bythemselves are not science.As the mathematician Jules Henri Poincare said,―Science is built with facts just as a house is built with bricks, but acollection of facts cannot be called science any more than a pile of bricks canbe called a house.‖
Most scientists start an investigation byfinding out what other scientists have learned about a particular problem.After known facts have been gathered, the scientist comes to the part of theinvestigation that requires considerable imagination.Poible solutions to theproblem are formulated.These poible solutions are called hypotheses.
In a way, any hypothesis is a leap into theunknown.It extends the scientist’s thinking beyond the known facts.Thescientist plans experiments, performs calculations, and makes observations totest hypotheses.Without hypothesis, further investigation lacks purpose anddirection.When hypotheses are confirmed, they are incorporated into theories.
28.Changing Roles of PublicEducation
One of the most important socialdevelopments that helped to make poible a shift in thinking about the role ofpublic education was the effect of the baby boom of the 1950\'s and 1960\'s onthe schools.In the 1920\'s, but especially in the Depreion conditions of the1930\'s, the United States experienced a declining birth rate --- every thousandwomen aged fifteen to forty-four gave birth to about 118 live children in 1920,89.2 in 1930, 75.8 in 1936, and 80 in 1940.With the growing prosperity broughton by the Second World War and the economic boom that followed it young peoplemarried and established households earlier and began to raise larger familiesthan had their predeceors during the Depreion.Birth rates rose to 102 perthousand in 1946,106.2 in 1950, and 118 in 1955.Although economics wasprobably the most important determinant, it is not the only explanation for thebaby boom.The increased value placed on the idea of the family also helps toexplain this rise in birth rates.The baby boomers began streaming into thefirst grade by the mid 1940\'s and became a flood by 1950.The public schoolsystem suddenly found itself overtaxed.While the number of schoolchildren rosebecause of wartime and postwar conditions, these same conditions made theschools even le prepared to cope with the food.The wartime economy meantthat few new schools were built between 1940 and 1945.Moreover, during the warand in the boom times that followed, large numbers of teachers left theirprofeion for better-paying jobs elsewhere in the economy.
Therefore in the 1950’s and 1960’s, the babyboom hit an antiquated and inadequate school system.Consequently, the ―custodial rhetoric‖ of the 1930’s and early 1940’s no longer made sense thatis, keeping youths aged sixteen and older out of the labor market by keepingthem in school could no longer be a high priority for an institution unable tofind space and staff to teach younger children aged five to sixteen.With thebaby boom, the focus of educators and of laymen interested in educationinevitably turned toward the lower grades and back to basic academic skills anddiscipline.The system no longer had much interest in offering nontraditional,new, and extra services to older youths.
29 Telecommuting
Telecommuting-- substituting the computerfor the trip to the job ----has been hailed as a solution to all kinds ofproblems related to office work.
For workers it promises freedom from the office,le time wasted in traffic, and help with child-care conflicts.Formanagement, telecommuting helps keep high performers on board, minimizestardine and absenteeism by eliminating commutes, allows periods of solitudefor high-concentration tasks, and provides scheduling flexibility.In someareas, such as Southern California and Seattle, Washington, local governmentsare encouraging companies to start telecommuting programs in order to reducerush-hour congestion and improve air quality.
But these benefits do not come easily.Making a telecommuting program work requires careful planning and anunderstanding of the differences between telecommuting realities and popularimages.
Many workers are seduced by rosy illusionsof life as a telecommuter.A computer programmer from New York City moves tothe tranquil Adirondack Mountains and stays in contact with her office viacomputer.A manager comes in to his office three days a week and works at homethe other two.An accountant stays home to care for her sick child; she hooksup her telephone modern connections and does office work between calls to thedoctor.
These are powerful images, but they are alimited reflection of reality.Telecommuting workers soon learn that it isalmost impoible to concentrate on work and care for a young child at the sametime.Before a certain age, young children cannot recognize, much le respect,the neceary boundaries between work and family.Additional child support isneceary if the parent is to get any work done.
Management too must separate the myth fromthe reality.Although the media has paid a great deal of attention totelecommuting in most cases it is the employee’s situation, not theavailability of technology that precipitates a telecommuting arrangement.
That is partly why, despite the widespreadpre coverage, the number of companies with work-at-home programs or policyguidelines remains small.
30 The origin of Refrigerators
By the mid-nineteenth century, the term―icebox‖ had entered the American language, but ice was still only beginning toaffect the diet of ordinary citizens in the United States.The ice trade grewwith the growth of cities.Ice was used in hotels, taverns, and hospitals, andby some forward-looking city dealers in fresh meat, fresh fish, and butter.After the Civil War( 1861-1865),as ice was used to refrigerate freight cars, italso came into household use.Even before 1880,half of the ice sold in NewYork, Philadelphia, and Baltimore, and one-third of that sold in Boston andChicago, went to families for their own use.This had become poible because anew household convenience, the icebox, a precursor of the modern refrigerator,had been invented.
Making an efficient icebox was not as easyas we might now suppose.In the early nineteenth century, the knowledge of thephysics of heat, which was eential to a science of refrigeration, wasrudimentary.The commonsense notion that the best icebox was one that preventedthe ice from melting was of course mistaken, for it was the melting of the icethat performed the cooling.Neverthele, early efforts to economize iceincluded wrapping up the ice in blankets, which kept the ice from doing itsjob.Not until near the end of the nineteenth century did inventors achieve thedelicate balance of insulation and circulation needed for an efficient icebox.
But as early as 1803, and ingenious Marylandfarmer, Thomas Moore, had been on the right track.He owned a farm about twentymiles outside the city of Washington, for which the village of Georgetown wasthe market center.When he used an icebox of his own design to transport hisbutter to market, he found that customers would pa up the rapidly melting stuff in the tubs of his competitorsto pay a premium price for his butter, still fresh and hard in neat, one-poundbricks.One advantage of his icebox, Moore explained, was that farmers would nolonger have to travel to market at night in order to keep their produce cool.31 British Columbia
British Columbia is the third largest Canadianprovinces, both in area and population.It is nearly 1.5 times as large asTexas, and extends 800 miles(1,280km) north from the United States border.Itincludes Canada’s entire west coast and the islands just off the coast.
Most of British Columbia is mountainous,with long rugged ranges running north and south.Even the coastal islands arethe remains of a mountain range that existed thousands of years ago.During thelast Ice Age, this range was scoured by glaciers until most of it was beneath thesea.Its peaks now show as islands scattered along the coast.
The southwestern coastal region has a humidmild marine climate.Sea winds that blow inland from the west are warmed by a current of warm water that flowsthrough the Pacific Ocean.As a result,winter temperatures average above freezing and summers are mild.These warmwestern winds also carry moisture from the ocean.
Inland from the coast, the winds from thePacific meet the mountain barriers of the coastal ranges and the Rocky Mountains.As they rise to crothe mountains, the winds are cooled, and their moisture begins to fall as rain.On some of the western slopes almost 200 inches (500cm) of rain fall each year.
More than half of British Columbia isheavily forested.On mountain slopes that receive plentiful rainfall, hugeDouglas firs rise in towering columns.These forest giants often grow to be asmuch as 300 feet(90m) tall, with diameters up to 10 feet(3m).More lumber isproduced from these trees than from any other kind of tree in North America.Hemlock, red cedar, and balsam fir are among the other trees found in BritishColumbia.
32 Botany
Botany, the study of plants, occupies apeculiar position in the history of human knowledge.For many thousands ofyears it was the one field of awarene about which humans had anything morethan the vaguest of insights.It is impoible to know today just what ourStone Age ancestors knew about plants, but form what we can observe ofpre-industrial societies that still exist a detailed learning of plants andtheir properties must be extremely ancient.This is logical.Plants are thebasis of the food pyramid for all living things even for other plants.Theyhave always been enormously important to the welfare of people not only for food,but also for clothing, weapons, tools, dyes, medicines, shelter, and a greatmany other purposes.Tribes living today in the jungles of the Amazon recognizeliterally hundreds of plants and know many properties of each.To them, botany,as such, has no name and is probably not even recognized as a special branch of― knowledge‖ at all.
Unfortunately, the more industrialized webecome the farther away we move from direct contact with plants, and the ledistinct our knowledge of botany grows.Yet everyone comes unconsciously on anamazing amount of botanical knowledge, and few people will fail to recognize arose, an apple, or an orchid.When our Neolithic ancestors, living in theMiddle East about 10,000 years ago, discovered that certain graes could beharvested and their seeds planted for richer yields the next season the firstgreat step in a new aociation of plants and humans was taken.Grains werediscovered and from them flowed the marvel of agriculture: cultivated crops.From then on, humans would increasingly take their living from the controlledproduction of a few plants, rather than getting a little here and a littlethere from many varieties that grew wild- and the accumulated knowledge of tensof thousands of years of experience and intimacy with plants in the wild wouldbegin to fade away.
33 Plankton浮游生物./ \'plжηktэn;`plжηktэn/
Scattered through the seas of the world arebillions of tons of small plants and animals called plankton.Most of theseplants and animals are too small for the human eye to see.They drift aboutlazily with the currents, providing a basic food for many larger animals.
Plankton has been described as theequivalent of the graes that grow on the dry land continents, and thecomparison is an appropriate one.In potential food value, however, planktonfar outweighs that of the land graes.One scientist has estimated that whilegraes of the world produce about 49 billion tons of valuable carbohydrateseach year, the sea’s plankton generates more than twice as much.
Despite its enormous food potential, littleeffect was made until recently to farm plankton as we farm graes on land.Nowmarine scientists have at last begun to study this poibility, especially asthe sea’s resources loom even more important as a means of feeding an expandingworld population.
No one yet has seriously suggested that ―plankton-burgers‖ may soon become popular around the world.As a poiblefarmed supplementary food source, however, plankton is gaining considerableinterest among marine scientists.
One type of plankton that seems to havegreat harvest poibilities is a tiny shrimp-like creature called krill.Growing to two or three inches long, krill provides the major food for thegreat blue whale, the largest animal to ever inhabit the Earth.Realizing thatthis whale may grow to 100 feet and weigh 150 tons at maturity, it is notsurprising that each one devours more than one ton of krill daily.
34 Raising Oysters
In the oysters were raised in much the sameway as dirt farmers raised tomatoes- by transplanting them.First, farmerelected the oyster bed, cleared the bottom of old shells and other debris,then scattered clean shells about.Next, they ‖planted‖ fertilized oyster eggs,which within two or three weeks hatched into larvae.The larvae drifted untilthey attached themselves to the clean shells on the bottom.There they remainedand in time grew into baby oysters called seed or spat.The spat grew larger bydrawing in seawater from which they derived microscopic particles of food.Before long, farmers gathered the baby oysters, transplanted them once moreinto another body of water to fatten them up.
Until recently the supply of wild oystersand those crudely farmed were more than enough to satisfy people’s needs.Buttoday the delectable seafood is no longer available in abundance.The problemhas become so serious that some oyster beds have vanished entirely.
Fortunately, as far back as the early 1900’smarine biologists realized that if new measures were not taken, oysters wouldbecome extinct or at best a luxury food.So they set up well-equippedhatcheries and went to work.But they did not have the proper equipment or theskill to handle the eggs.They did not know when, what, and how to feed thelarvae.And they knew little about the predators that attack and eat babyoysters by the millions.They failed, but they doggedly kept at it.Finally, inthe 1940’s a significant breakthrough was made.
The marine biologists discovered that byraising the temperature of the water, they could induce oysters to spawn notonly in the summer but also in the fall, winter, and spring.Later they developed a technique for feeding the larvaeand rearing them to spat.Going still further, they succeeded in breeding newstrains that were resistant to diseases, grew faster and larger, and flourishedin water of different salinities and temperatures.In addition, the cultivatedoysters tasted better!
35.Oil Refining
An important new industry, oil refining,grew after the Civil war.Crude oil, or petroleum – a dark, thick ooze from theearth – had been known for hundreds of years, but little use had ever been madeof it.In the 1850’s Samuel M.Kier, a manufacturer in western Pennsylvania,began collecting the oil from local seepages and refining it into kerosene.Refining, like smelting, is a proce of removing impurities from a rawmaterial.
Kerosene was used to light lamps.It was acheap substitute for whale oil, which was becoming harder to get.Soon there was a large demand forkerosene.People began to search for new supplies of petroleum.
The first oil well was drilled by E.L.Drake, a retired railroad conductor.In 1859 he began drilling in Titusville,Pennsylvania.The whole venture seemed so impractical and foolish thatonlookers called it ― Drake’s Folly‖.But when he had drilled down about 70feet(21 meters), Drake struck oil.His well began to yield 20 barrels of crudeoil a day.
News of Drake’s succe brought oilprospectors to the scene.By the early 1860’s these wildcatters were drillingfor ― black gold‖ all over western Pennsylvania.The boom rivaled theCalifornia gold rush of 1848 in its excitement and Wild West atmosphere.And itbrought far more wealth to the prospectors than any gold rush.
Crude oil could be refined into manyproducts.For some years kerosene continued to be the principal one.It waold in grocery stores and door-to-door.In the 1880’s refiners learned how tomake other petroleum products such as waxes and lubricating oils.Petroleum wasnot then used to make gasoline or heating oil.
36.Plate Tectonics and Sea-floorSpreading
The theory of plate tectonics describes themotions of the lithosphere, the comparatively rigid outer layer of the Earththat includes all the crust and part of the underlying mantle.Thelithosphere(n.[地]岩石圈)is divided into a few dozen platesof various sizes and shapes, in general the plates are in motion with respectto one another.A mid-ocean ridge is a boundary between plates where newlithospheric material is injected from below.As the plates diverge from amid-ocean ridge they slide on a more yielding layer at the base of thelithosphere.
Since the size of the Earth is eentiallyconstant, new lithosphere can be created at the mid-ocean ridges only if anequal amount of lithospheric material is consumed elsewhere.The site of thisdestruction is another kind of plate boundary: a subduction zone.There oneplate dives under the edge of another and is reincorporated into the mantle.Both kinds of plate boundary are aociated with fault systems, earthquakes andvolcanism, but the kinds of geologic activity observed at the two boundariesare quite different.
The idea of sea-floor spreading actuallypreceded the theory of plate tectonics.In its original version, in the early1960’s, it described the creation and destruction of the ocean floor, but itdid not specify rigid lithospheric plates.The hypothesis was substantiatedsoon afterward by the discovery that periodic reversals of the Earth’s magneticfield are recorded in the oceanic crust.As magma rises under the mid-oceanridge, ferromagnetic minerals in the magma become magnetized in the directionof the magma become magnetized in the direction of the geomagnetic field.Whenthe magma cools and solidifies, the direction and the polarity of the field arepreserved in the magnetized volcanic rock.Reversals of the field give rise toa series of magnetic stripes running parallel to the axis of the rift.Theoceanic crust thus serves as a magnetic tape recording of the history of thegeomagnetic field that can be dated independently; the width of the stripesindicates the rate of the sea-floor spreading.
37 Icebergs
Icebergs are among nature’s most spectacularcreations, and yet most people have never seen one.A vague air of mysteryenvelops them.They come into being ----- somewhere ------in faraway, frigidwaters, amid thunderous noise and splashing turbulence, which in most cases noone hears or sees.They exist only a short time and then slowly waste away justas unnoticed.
Objects of sheerest beauty they have beencalled.Appearing in an endle variety of shapes, they may be dazzlinglywhite, or they may be glay blue, green or purple, tinted faintly of in darkerhues.They are graceful, stately, inspiring ----- in calm, sunlight seas.
But they are also called frightening anddangerous, and that they are ---- in thenight, in the fog, and in storms.Even in clear weather one is wise to stay asafe distance away from them.Most of their bulk is hidden below the water, sotheir underwater parts may extend out far beyond the visible top.Also, theymay roll over unexpectedly, churning the waters around them.
Icebergs are parts of glaciers that breakoff, drift into the water, float about awhile, and finally melt.Icebergsafloat today are made of snowflakes that have fallen over long ages of time.They embody snows that drifted down hundreds, or many thousands, or in somecases maybe a million years ago.The snows fell in polar regions and on coldmountains, where they melted only a little or not at all, and so collected togreat depths over the years and centuries.
As each year’s snow accumulation lay on thesurface, evaporation and melting caused the snowflakes slowly to lose theirfeathery points and become tiny grains of ice.When new snow fell on top of theold, it too turned to icy grains.So blankets of snow and ice grains mountedlayer upon layer and were of such great thickne that the weight of the upperlayers compreed the lower ones.With time and preure from above, the manysmall ice grains joined and changed to larger crystals, and eventually thedeeper crystals merged into a solid ma of ice.
38 Topaz
Topaz is a hard, transparent mineral.It isa compound of aluminum, silica, and fluorine.Gem topaz is valuable.Jewelerscall this variety of the stone ―precious topaz‖.The best-known precious topazgems range in color from rich yellow to light brown or pinkish red.Topaz isone of the hardest gem minerals.In the mineral table of hardne, it has arating of 8, which means that a knife cannot cut it, and that topaz willscratch quartz.
The golden variety of precious topaz isquite uncommon.Most of the world’s topaz is white or blue.The white and bluecrystals of topaz are large, often weighing thousands of carats.For thisreason, the value of topaz does not depend so much on its size as it does withdiamonds and many other precious stones, where the value increases about fourtimes with each doubling of weight.The value of a topaz is largely determinedby its quality.But color is also important: blue topaz, for instance, is oftenirradiated to deepen and improve its color.
Blue topaz is often sold as aquamarine and avariety of brown quartz is widely sold as topaz.The quartz is much le brilliantand more plentiful than true topaz.Most of it is variety of amethyst: thatheat has turned brown.
NOTE: topaz/ \'tэupжz; `topжz/ n (a) [U] transparentyellow mineral 黄玉（矿物）. (b) [C] semi-preciousgem cut from this 黄玉;黄宝石.
39 The Salinity of Ocean Waters
If the salinity of ocean waters is analyzed,it is found to vary only slightly from place to place.Neverthele, some ofthese small changes are important.There are three basic procees that cause achange in oceanic salinity.One of these is the subtraction of water from theocean by means of evaporation--- conversion of liquid water to water vapor.Inthis manner the salinity is increased, since the salts stay behind.If this iscarried to the extreme, of course, white crystals of salt would be left behind.
The opposite of evaporation isprecipitation, such as rain, by which water is added to the ocean.Here theocean is being diluted so that the salinity is decreased.This may occur inareas of high rainfall or in coastal regions where rivers flow into the ocean.Thus salinity may be increased by the subtraction of water by evaporation, ordecreased by the addition of fresh water by precipitation or runoff.
Normally, in tropical regions where the sunis very strong, the ocean salinity is somewhat higher than it is in other partsof the world where there is not as much evaporation.Similarly, in coastal regionswhere rivers dilute the sea, salinity is somewhat lower than in other oceanicareas.
A third proce by which salinity may bealtered is aociated with the formation and melting of sea ice.When sea wateris frozen, the diolved materials are left behind.In this manner, sea waterdirectly materials are left behind.In this manner, sea water directly beneathfreshly formed sea ice has a higher salinity than it did before the iceappeared.Of course, when this ice melts, it will tend to decrease the salinityof the surrounding water.
In the Weddell Sea Antarctica, the densestwater in the oceans is formed as a result of this freezing proce, whichincreases the salinity of cold water.This heavy water sinks and is found inthe deeper portions of the oceans of the world.
NOTE：
salinity/ sэ\'linэti; sэ`linэti/
n[U] the high salinity of sea water 海水的高含盐量.-à>>saline / \'seilain; US -li:n; `selin/
1.adj[attrib 作定语] (fml 文) containing salt; salty 含盐的; 咸的: * a saline lake 盐湖
* saline springs 盐泉
* saline solution, eg as used for gargling,storing contact lenses, etc 盐溶液（如用于漱喉、存放隐形眼镜等）.2.n [U] (medical 医) solutionof salt and water 盐水.
40 Cohesion-tension Theory
Atmospheric preure can support a column ofwater up to 10 meters high.But plants can move water much higher; the sequoiatree can pump water to its very top more than 100 meters above the ground.Until the end of the nineteenth century, the movement of water in trees andother tall plants was a mystery.Some botanists hypothesized that the livingcells of plants acted as pumps.But many experiments demonstrated that thestems of plants in which all the cells are killed can still move water toappreciable heights.Other explanations for the movement of water in plantshave been based on root preure, a push on the water from the roots at thebottom of the plant.But root preure is not nearly great enough to push waterto the tops of tall trees.Furthermore, the conifers, which are among thetallest trees, have unusually low root preures.
If water is not pumped to the top of a talltree, and if it is not pushed to the top of a tall tree, then we may ask: howdoes it get there? According to the currently accepted cohesion-tension theory,water is pulled there.The pull on a rising column of water in a plant resultsfrom the evaporation of water at the top of the plant.As water is lost fromthe surface of the leaves, a negative preure, or tension, is created.Theevaporated water is replaced by water moving from inside the plant in unbrokencolumns that extend from the top of a plant to its roots.The same forces thatcreate surface tension in any sample of water are responsible for themaintenance of these unbroken columns of water.When water is confined in tubesof very small bore, the forces of cohesion (the attraction between watermolecules) are so great that the strength of a column of water compares withthe strength of a steel wire of the same diameter.This cohesive strengthpermits columns of water to be pulled to great heights without being broken.41.American black bears
American black bears appear in a variety ofcolors despite their name.In the eastern part of their range, most of thesebrown, red, or even yellow coats.To the north, the black bear is actually grayor white in color.Even in the same litter, both brown and black furred bearsmay be born.
Black bears are the smallest of all Americanbears, ranging in length from five to six feet, weighing from three hundred tofive hundred pounds Their eyes and ears are small and their eyesight andhearing are not as good as their sense of smell. Like all bears, the black bear is timid,clumsy, and rarely dangerous , but if attacked, most can climb trees and coverground at great speeds.When angry or frightened, it is a formidable enemy.
Black bears feed on leaves, herbs.Fruit,berries, insects, fish, and even larger animals.One of the most interestingcharacteristics of bears, including the black bear, is their winter sleep.Unlike squirrels, woodchucks, and many other woodland animals, bears do notactually hibernate.Although the bear does not during the winter moths,sustaining itself from body fat, its temperature remains almost normal, and itbreathes regularly four or five times per minute.
Most black bears live alone, except duringmating season.They prefer to live in caves, hollow logs, or dense thickets.Alittle of one to four cubs is born in January or February after a gestationperiod of six to nine months, and they remain with their mother until they arefully grown or about one and a half years old.Black bears can live as long asthirty years in the wild , and even longer in game preserves set aside forthem.
42.Coal-fired power plants
The invention of the incandescent light bulbby Thomas A.Edison in 1879 created a demand for a cheap, readily availablefuel with which to generate large amounts of electric power.Coal seemed to fitthe bill, and it fueled the earliest power stations.(which were set up at theend of the nineteenth century by Edison himself).As more power plants wereconstructed throughout the country, the reliance on coal increased throughoutthe country, the reliance on coal increased.Since the First World War,coal-fired power plants had a combined in the United States each year.In 1986such plants had a combined generating capacity of 289,000 megawatts andconsumed 83 percent of the nearly 900 million tons of coal mined in the countrythat year.Given the uncertainty in the future growth of the nearly 900 milliontons of coal mined in the country that year.Given the uncertainty in thefuture growth of nuclear power and in the supply of oil and natural gas,coal-fired power plants could well provide up to 70 percent of the electricpower in the United States by the end of the century.
Yet, in spite of the fact that coal has longbeen a source of electricity and may remain on for many years(coal representsabout 80 percent of United States foil-fuel reserves), it has actually neverbeen the most desirable foil fuel for power plants.Coal contains le energyper unit of weight than weight than natural gas or oil; it is difficult totransport, and it is aociated with a host of environmental iues, among themacid rain.Since the late 1960’s problems of emiion control and wastedisposal have sharply reduced the appeal of coal-fired power plants.The costof ameliorating these environment problems along with the rising cost ofbuilding a facility as large and complex as a coal-fired power plant, have alsomade such plants le attractive from a purely economic perspective. Changes in the technological base ofcoal-fired power plants could restore their attractivene, however.Whereaome of these changes are intended mainly to increase the productivity ofexisting plants, completely new technologies for burning coal cleanly are alsobeing developed.
43.Statistics
There were two widely divergent influenceson the early development of statistical methods.Statistics had a mother whowas dedicated to keeping orderly records of government units (states andstatistics come from the same Latin root status) and a gentlemanly gamblingfather who relied on mathematics to increase his skill at playing the odds ingames of chance.The influence of the mother on the offspring, statistics, isrepresented by counting, measuring, describing, tabulating, ordering, and thetaking of censuses—all of which led to modern descriptive statistics.From theinfluence of the father came modern inferential statistics, which is basedsquarely on theories of probability.
Describing collections involves tabulating,depicting and describing collections of data.These data may be quantitativesuch as measures of height, intelligence or grade level------variables that arecharacterized by an underlying continuum---or the data may representqualitative variables, such as sex, college major or personality type.Largemaes of data must generally undergo a proce of summarization or reductionbefore they are comprehensible.Descriptive statistics is a tool for describingor summarizing or reducing to comprehensible form the properties of anotherwise unwieldy ma of data.
Inferential statistics is a formalized bodyof methods for solving another cla of problems that present great of problemscharacteristically involves attempts to make predictions using a sample ofobservations.For example, a school superintendent wishes to determine theproportion of children in a large school system who come to school withoutbreakfast, have been vaccinated for flu, or whatever.Having a little knowledgeof statistics, the superintendent would know that it is unneceary andinefficient to question each child: the proportion for the sample of as few as100 children.Thus , the purpose of inferential statistics is to predict or estimatecharacteristics of a population from a knowledge of the characteristics of onlya sample of the population.
44.Obtaining Fresh water fromicebergs
你好，我是胖胖：——）
The concept of obtaining fresh water fromicebergs that are towed to populated areas and arid regions of the world wasonce treated as a joke more appropriate to cartoons than real life.But now itis being considered quite seriously by many nations, especially sincescientists have warned that the human race will outgrow its fresh water supplyfaster than it runs out of food. Glaciers are a poible source of freshwater that has been overlooked until recently.Three-quarters of the Earth’sfresh water supply is still tied up in glacial ice, a reservoir of untappedfresh water so immense that it could sustain all the rivers of the world for1,000 years.Floating on the oceans every year are 7,659 trillion metric tonsof ice encased in 10000 icebergs that break away from the polar ice caps, morethan ninety percent of them from Antarctica.
Huge glaciers that stretch over the shallowcontinental shelf give birth to icebergs throughout the year.Icebergs are notlike sea ice, which is formed when the sea itself freezes, rather, they areformed entirely on land, breaking off when glaciers spread over the sea.Asthey drift away from the polar region, icebergs sometimes move mysteriously ina direction opposite to the wind, pulled by subsurface currents.Because theymelt more slowly than smaller pieces of ice, icebergs have been known to drift asfar north as 35 degrees south of the equator in the Atlantic Ocean.To corralthem and steer them to parts of the world where they are needed would not betoo difficult.
The difficulty arises in other technicalmatters, such as the prevention of rapid melting in warmer climates and thefunneling of fresh water to shore in great volume.But even if the icebergslost half of their volume in towing, the water they could provide would be farcheaper than that produced by desalinization, or removing salt from water.
45.The source of Energy
A summary of the physical and chemicalnature of life must begin, not on the Earth, but in the Sun; in fact, at theSun’s very center.It is here that is to be found the source of the energy thatthe Sun constantly pours out into space as light and heat.This energy islibrated at the center of the Sun as billions upon billions of nuclei ofhydrogen atoms collide with each other and fuse together to form nuclei ofhelium, and in doing so, release some of the energy that is stored in thenuclei of atoms.The output of light and heat of the Sun requires that some 600million tons of hydrogen be converted into helium in the Sun every second.Thisthe Sun has been doing for several thousands of millions of year.
The nuclear energy is released at the Sun’scenter as high-energy gamma radiation, a form of electromagnetic radiation likelight and radio waves, only of very much shorter wavelength.This gammaradiation is absorbed by atoms inside the Sun to be reemitted at slightlylonger wavelengths.This radiation , in its turn is absorbed and reemitted.Asthe energy filters through the layers of the solar interior, it paes throughthe X-ray part of the spectrum eventually becoming light.At this stage, it hasreached what we call the solar surface, and can escape into space without beingabsorbed further by solar atoms.A very small fraction of the Sun’s light andheat is emitted in such directions that after paing unhindered throughinterplanetary space, it hits the Earth.
46.Visionby胖胖
Human vision like that of other primates hasevolved in an arboreal environment.In the dense complex world of a tropicalforest, it is more important to see well that to develop an acute sense ofsmell.In the course of evolution members of the primate line have acquiredlarge eyes while the snout has shrunk to give the eye an unimpeded view.Ofmammals only humans and some primates enjoy color vision.The red flag is blackto the bull.Horses live in a monochrome world .light visible to human eyeshowever occupies only a very narrow band in the whole electromagnetic spectrum.Ultraviolet rays are invisible to humans though ants and honeybees aresensitive to them.Humans though ants and honeybees are sensitive to them.Humans have no direct perception of infrared rays unlike the rattlesnake whichhas receptors tuned into wavelengths longer than 0.7 micron.The world wouldlook eerily different if human eyes were sensitive to infrared radiation.Theninstead of the darkne of night, we would be able to move easily in a strangeshadowle world where objects glowed with varying degrees of intensity.Buthuman eyes excel in other ways.They are in fact remarkably discerning in colorgradation.The color sensitivity of normal human vision is rarely surpaedeven by sophisticated technical devices.
47 Folk Cultures胖胖提供：）
A folk culture is a small isolated,cohesive, conservative, nearly self-sufficient group that is homogeneous incustom and race with a strong family or clan structure and highly developedrituals.Order is maintained through sanctions based in the religion or familyand interpersonal.Relationships are strong.Tradition is paramount, and changecomes infrequently and slowly.There is relatively little division of laborinto specialized duties.Rather, each person is expected to perform a greatvariety of tasks, though duties may differ between the sexes.Most goods arehandmade and subsistence economy prevails.Individualism is weakly developed infolk cultures as are social claes.Unaltered folk cultures no longer exist inindustrialized countries such as the United States and Canada.Perhaps thenearest modern equivalent in Anglo America is the Amish, a German Americanfarming sect that largely renounces the products and labor saving devices of the industrial age.In Amish areas, horsedrawn buggies still serve as a local transportation device and the faithful arenot permitted to own automobiles.The Amish’s central religious concept ofDemut ―humility‖, clearly reflects theweakne of individualism and social cla so typical of folk cultures andthere is a corresponding strength of Amish group identity.Rarely do the Amishmarry outside their sect.The religion, a variety of the Mennonite faith,provides the principal mechanism for maintaining order.
By contrast a popular culture is a largeheterogeneous group often highly individualistic and a pronounced manyspecialized profeions.Secular institutions of control such as the police andarmy take the place of religion and family in maintaining order, and amoney-based economy prevails.Because of these contrasts, ―popular‖ may beviewed as clearly different from ―folk‖.The popular is replacing the folk inindustrialized countries and in many developing nations.Folk-made objects giveway to their popular equivalent, usually because the popular item is morequickly or cheaply produced, is easier or time saving to use or leads moreprestige to the owner.
48 Bacteriaby胖胖：）
Bacteria are extremely small living things.While we measure our own sizes in inches or centimeters, bacterial size ismeasured in microns.One micron is a thousandth of a millimeter: a pinhead isabout a millimeter acro.Rod-shaped bacteria are usually from two to fourmicrons long, while rounded ones are generally one micron in diameter.Thus ifyou enlarged a rounded bacterium a thousand times, it would be just about thesize of a pinhead.An adult human magnified by the same amount would be over amile(1.6 kilometer) tall.
Even with an ordinary microscope, you mustlook closely to see bacteria.Using a magnification of 100 times, one findsthat bacteria are barely visible as tiny rods or dots.One cannot make outanything of their structure.Using special stains, one can see that somebacteria have attached to them wavy-looking ―hairs‖ called flagella.Othershave only one flagellum.The flagella rotate, pushing the bacteria through thewater.Many bacteria lack flagella and cannot move about by their own power,while others can glide along over surfaces by some little-understood mechanism.
From the bacteria point of view, the worldis a very different place from what it is to humans.To a bacterium water is asthick as molaes is to us.Bacteria are so small that they are influenced bythe movements of the chemical molecules around them.Bacteria under themicroscope, even those with no flagella, often bounce about in the water.Thisis because they collide with the watery molecules and are pushed this way andthat.Molecules move so rapidly that within a tenth of a second the moleculesaround a bacteria have all been replaced by new ones; even bacteria withoutflagella are thus constantly exposed to a changing environment.
49 Sleep呵呵，还是胖胖：）
Sleet is part of a person’s daily activitycycle.There are several different stages of sleep, and they too occur incycles.If you are an average sleeper, your sleep cycle is as follows.When youfist drift off into slumber, your eyes will roll about a bit, you temperaturewill drop slightly, your muscles will relax, and your breathing well slow andbecome quite regular.Your brain waves slow and become quite regular.Yourbrain waves slow down a bit too, with the alpha rhythm of rather fast waves 1sleep.For the next half hour or so, as you relax more and more, you will driftdown through stage 2 and stage 3 sleep.The lower your stage of sleep.sloweryour brain waves will be.Then about 40to 69 minutes after you lose consciousneyou will have reached the deepest sleep of all.Your brain will show the largeslow waves that are known as the delta rhythm.This is stage 4 sleep.
You do not remain at this deep fourth stageall night long, but instead about 80 minutes after you fall into slumber, yourbrain activity level will increase again slightly.The delta rhythm willdisappear, to be replaced by the activity pattern of brain waves.Your eyeswill begin to dart around under your closed eyelids as if you were looking atsomething occurring in front of you.This period of rapid eye movement lastsfor some 8 to 15 minutes and is called REM sleep.It is during REM sleepperiod, your body will soon relax again, your breathing will slip gently backfrom stage 1 to stage 4 sleep----only to rise once again to the surface of nearconsciousne some 80 minutes later.
50.Cells and Temperature
Cells cannot remain alive outside certainlimits of temperature and much narrower limits mark the boundaries of effectivefunctioning.Enzyme systems of mammals and birds are most efficient only withina narrow range around 37C;a departure of a few degrees from this valueseriously impairs their functioning.Even though cells can survive widerfluctuations the integrated actions of bodily systems are impaired.Otheranimals have a wider tolerance for changes of bodily temperature.
For centuries it has been recognized thatmammals and birds differ from other animals in the way they regulate bodytemperature.Ways of characterizing the difference have become more accurateand meaningful over time, but popular terminology still reflects the old divisioninto ―warm-blooded‖ and ―cold-blooded‖ species; warm-blooded included mammalsand birds whereas all other creatures were considered cold-blooded.As morespecies were studied, it became evident that this claification wasinadequate.A fence lizard or a desert iguana—each cold-blooded----usually hasa body temperature only a degree or two below that of humans and so is notcold.Therefore the next distinction was made between animals that maintain aconstant body temperature, called home0therms, and those whose body temperaturevaries with their environments, called poikilotherms.But this claificationalso proved inadequate, because among mammals there are many that vary theirbody temperatures during hibernation.Furthermore, many invertebrates that livein the depths of the ocean never experience change in the depths of the oceannever experience change in the chill of the deep water, and their bodytemperatures remain constant.
