transmission-countershaft reverse gear

例句：

1. 1. The car's transmission system is designed to provide smooth and efficient shifting between gears.
   汽车的传动系统设计用来提供平滑且高效的换挡。
2. 2. The engineer used the countershaft reverse gear to help the heavy machinery move more easily.
   工程师使用倒档齿轮帮助重型机械更容易移动。
3. 3. During a critical maintenance period, the technician had to perform a series of transmission-countershaft reverse gear operations to ensure the machinery's continued operation.
   在关键的维护时期，技术员必须执行一系列的传动轴倒档齿轮操作以确保机器的持续运行。