vacuum oil filling

例句：

1. 1. The vacuum oil filling is a crucial part of the engine's maintenance.
   真空加油是发动机维护中至关重要的一部分。
2. 2. The engineer carefully filled the vacuum oil in the engine.
   工程师仔细地给发动机中的真空油加注。
3. 3. The vacuum oil filling system helps to prevent engine wear and tear.
   真空加油系统有助于防止发动机磨损和损坏。