夏夜的巨大帘幕徐徐拉起,成群的蝙蝠开始捕虫觅食,尽管黑暗笼罩天上地下,蝙蝠却能掌握方位,盘旋如意。科学家经过几个世纪的努力,才彻底揭开蝙蝠飞翔的秘密,它嘴里不停地发出一束束超声波,每秒钟都有两万次以上的振动频率. The huge curtain of summer night slowly pull up, flocks of bats began to catch insects for food, although the darkness enveloped heaven and earth, the bat can grasp the orientation, circling wishful. After centuries of hard work, scientists have completely uncovered the secret of flying bats, sending a bunch of ultrasonic waves in their mouths constantly, each with 20,000 or more vibration frequencies.