How dose Ultrasonic work? Untrasonic are like bat ears it shout out thing and it get back so it will help it to not to bump in things.If you cover one of bat’s ears or mouth and put it in a dark room it will bump every were! When people find out that bat use untrasonic , it help thing in the world , an exzanmple , like airplane , the are plane will not bump to other airplane because untrasonic help it.It work like this .
《ev3 超声波原理.doc》
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