说明：  超声波测距器，可以应用于汽车倒车、建筑施工工地以及一些工业现场的位置监控，也可用于如液位、井深、管道长度的测量等场合。
(Ultrasonic ranging, can be applied in automobile reverse construction site, and the position control, also can be used for such as level, deep, pipe length measurement etc.)