lubricating oil and piston cooling oil pump

例句：

1. 1.The engine needs lubricating oil to keep it running smoothly.
   发动机需要润滑油来保持平稳运行。
2. 2. The piston cooling oil pump is essential for maintaining the engine's temperature.
   活塞冷却油泵对于保持发动机温度至关重要。
3. 3. The oil pump is responsible for dispensing the lubricating oil to the engine.
   油泵负责将润滑油分配到发动机中。