main and return cam

例句：

1. 1. The main and returncams are responsible for controlling the speedof the car's engine.
   主控器和返回控制器负责控制汽车引擎的速度。
2. 2. The engineers were able to adjustthe main and return cams tooptimize the performance of the engine.
   工程师们能够调整主控器和返回控制器以优化发动机的性能。
3. 3. The new design incorporates a more sophisticated main and returncam system to improve fuel efficiency.
   新设计采用了更复杂的主控器和返回控制器系统以提高燃油效率。