cylinder cock stem

例句：

1. 1.The cylinder cock stem is used to adjust the oil level in the engine.
   气缸顶杆用于调整发动机中的油位。
2. 2.The cylinder cock stem was a crucial part of the car's engine.
   气缸顶杆是汽车引擎中一个至关重要的部分。
3. 3.The cylinder cock stem was removed to replace the worn out part.
   为了更换磨损的部分，需要拆卸气缸顶杆。