valvecock

例句：

1. 1.The engineer needs to check the valves on the pipeline for leaks.
   工程师需要检查管道上的阀门是否有泄漏。
2. 2. The farmer used a valve cock to turn off the water supply to the fields.
   农民使用一个阀门活门来关闭水源供应给田地。
3. 3.The valve cock was rusted and needed to be replaced.
   阀门活门生锈了，需要更换。