润滑剂

例句：

1. 1. The engine needs a new lubricant to keep it running smoothly.
   发动机需要新的润滑油来保持顺畅运行。
2. 2.Lubricants are used to reduce friction between moving parts.
   润滑油用于减少移动部件之间的摩擦。
3. 3. The car's engine has been damaged by the old lubricant.
   汽车的发动机因旧润滑油而受损。