I knew...when it happened, a lot of people had died.

我知道……它发生的时候，死了很多人。

911事件的影响 - SpeakingMax英语口语达人

When that happened it would destroy the economy.

当这种现象发生时，将会摧毁经济。

耶鲁公开课 - 金融市场课程节选

It's happened over the course of millions of years of human evolution, but it's happened also in a relatively recent time frame when we think about the American diet and what people are eating, but also the world diet of course.

它们发生在人类数百万年的演化历程中,在近现代,当我们考虑美国人的食谱,当然也包括全世界的食谱,同样在发生着这些变革

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

when the economic crisis happened. It was... yeah.

就在经济危机发生的时候。那……是的。

经济危机的影响 - SpeakingMax英语口语达人