valve rocker lever ball end

例句：

1. 1. The valve on the engine is responsible for controlling air flow.
   发动机上的阀门负责控制空气流动。
2. 2. The valves in the piston are designed to allow gases to escape during compression.
   活塞中的阀门设计为在压缩过程中允许气体逸出。
3. 3. The valve was replaced due to a leak that had been causing problems.
   由于泄漏问题，阀门被更换了。