They may happen to do something useful.

语言学家可能恰好做了某件有用的事情。

We run enormous models on supercomputers; this is what I happen to do.

我们在超级电脑上运算大量的模型，这正是我所做的研究。

When you read your newspaper or paper or television, argue with your friends in the pub or whatever you happen to do, I want you to identify when arguments come up.

当你读到报纸，论文，或者看电视的时候，与你的朋友在酒吧辩论，不管是什么，当论点产生的时候，我想让你们去识别。

You don't happen to know his name, do you?

你不会碰巧知道他的名字吧？

"Sometimes, bad things happen again and again, and we never understand why, "Michele said, wishing ther was something she could do to ease her pain.

“有时候，糟糕的事情会一次又一次地发生，我们永远不知道为什么，”米歇尔说，希望她能做点什么来减轻她的痛苦。