We have what at first seems like a pretty attractive theory, but then, how do you explain the fact that this has happened before?

我们提出了一开始看起来很有吸引力的理论，但是接下来，你要如何解释以前也发生过这种情况呢？

youdao

All this has happened because you couldn't be bothered to give me the message.

就是因为你嫌麻烦没通知我，才出了这事。

《牛津词典》

He thinks his heart is going to stop because he can't possibly know how this has happened.

他认为他的心脏要停止跳动了，因为他不可能知道这是怎么发生的。

youdao

He says this is a very huge increase compared to what has happened in the past.

VOA: special.2009.06.03

There are signs all over the place that this has happened.

广泛的迹象表明这一点的确存在

耶鲁公开课 - 欧洲文明课程节选

This has happened so many times in history that governments around the world now regulate banks and tell them that they have to hold a minimum amount of reserves and have a minimum amount of capital.

这在历史上已经发生多次了,如今,各国政府都在进行银行监管,并且告诉他们,他们必须留存最小金额的准备金,以及最小金额的资本金

耶鲁公开课 - 金融市场课程节选

In fact, this has happened twice in recent years, with alfalfa and sugar beets.

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This has happened in the past though it was met with a public backlash.

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"Not the first time this has happened and it won't be the last, " says one guest.

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