main exhaust port

例句：

1. 1.The car has a main exhaust port on the back.
   这辆车的后面有一个主排气口。
2. 2. The factory uses a main exhaust port to vent its exhaust gases.
   工厂使用一个主排气口来排放其废气。
3. 3.The engineer replaced the main exhaust port with a more efficient one.
   工程师用一个更高效的主排气口替换了原来的。