back and forth motion meaning in Chinese
往复运动
Examples
- When sound waves enter the cochlea , which is really a tube coiled around , they set a membrane into a back and forth motion and cause a new wave
当声波进入耳蜗这条盘旋的管道，它令薄膜前后移动并且产生新的波动。 - Hold the floss tightly between the thumbs and forefingers of both hands , leaving about 2 cm of floss in between . use a back and forth motion to gently slide the floss towards the gingivae between the teeth
用双手的拇指及食指操纵一段约2厘米长的牙线，前后拉动牙线并慢慢地让它滑进牙缝内；