reverse gears

例句：

1. 1.The car has a reverse gear that allows you to reverse the direction of the engine.
   这辆车有一个反向齿轮，可以让你逆转发动机的方向。
2. 2. In order to start the engine, you need to press the reverse gear first.
   为了启动发动机，你需要先按下反向齿轮。
3. 3.The engineer used the reverse gear to shift the heavy load onto the truck's wheels.
   工程师使用反向齿轮将重物转移到卡车的轮子上。