middle machine oil

例句：

1. 1.The middle machine oil needs to be changed regularly to ensure smooth operation of the machine.
   中间机器油需要定期更换，以保证机器的正常运行。
2. 2. The old engine is in need of some middle machine oil to keep it running smoothly.
   旧引擎需要一些中间机器油来保持其平稳运行。
3. 3.The mechanics used a special middle machine oil to lubricate the gears and prevent them from seizing up.
   机械师使用一种特殊的中间机器油来润滑齿轮，防止它们卡住。