John：
Do you fasten your seat belt when you're flying?
你坐飞机系安全带吗？
Mary：
Of course I do. It's the first thing I do to keep safe.
当然了，安全啊。
John：
I rarely fasten my seat belt and I'm still fine.
我很少系，也没出什么事啊。
Mary：
Well, man, you'd better fasten it next time.
老兄，我劝你下次还是老老实实的系上吧。