Now that unfortunately happens quite regularly.

这样的不幸时有发生。

普林斯顿公开课 - 人性课程节选

These things happen from time to time, but they happen with enough regularity that there's something we really want to understand as a systematic-- as a systematic phenomenon.

这样的事情时有发生,而且具有一定规律性,所以我们希望能够,弄清楚这其中的,系统性现象

耶鲁公开课 - 金融市场课程节选

And these--some version of these things happen all of the time.

类似的事情时有发生。

耶鲁公开课 - 心理学导论课程节选

When you get a wound several things start to happen.

受伤时有好几个生理过程会发生

耶鲁公开课 - 生物医学工程探索课程节选