They believed him to be insane.

他们认为他疯了。

youdao

He must be insane to drive so fast.

他把车开得这么快，一定是疯了。

youdao

Often, border police thought he must be insane. Some said they would permit him to cross, but not his motorcycle.

通常，边防警察都会认为他是一个精神病，有些人说，他们允许他过去，但不允许他的摩托车过去。

youdao

Often, border police thought he must be insane.

VOA: special.2009.01.14

The gunman was found to be insane.

VOA: special.2010.04.29

We were over the hill before this insane movement could be discovered and stopped.

VOA: special.2010.03.27

The situation would be insane if it were happening in some other industry besides health care.

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No one knows whether recycled scrap will be included (it would be insane if it were).

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And anyone who has children would be insane to go for non-traditional employment over big business or government work.

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