primary air inlet

例句：

1. 1. The primaryair inlet is located at the topof the engine.
   主空气入口位于发动机顶部。
2. 2. The primary air inlet is designedto improve fuel efficiency.
   主空气入口设计用来提高燃油效率。
3. 3. The primary air inlet is responsible for filtering out pollutants from the exhaust gases.
   主空气入口负责过滤废气中的污染物。