main air valve

例句：

1. 1. The main air valveis located at the top of the engineblock.
   主气阀位于发动机缸体顶部。
2. 2. Main air valves are used tocontrol the flow of air into the engine.
   主气阀用于控制空气流入发动机的流动。
3. 3. The main air valve was damagedduring the accident and had to be replaced.
   事故中主气阀受损，需要更换。