The purpose of the propeller
飞机螺旋桨的用处
A: "What's the purpose of the propeller?"
B: "To keep the pilot cool. If you don't think so, just stop it and watch him sweat!"
A：飞机的螺旋桨有什么用?
B：为了保持飞行员凉爽。不信的话，只要停止螺旋桨转动看看飞行员会不会满头大汗。
