How foolish I am to entertain doubts.

我心存疑虑是多么愚蠢啊。

《柯林斯英汉双解大词典》

Oh, how foolish I was!

咳，我多么愚蠢!

《新英汉大辞典》

The teachers looked my way and talked about how foolish I looked in my new jacket.

老师们看着我，说我穿着新夹克看起来有多傻。

youdao

When I tell you," said Joseph Taylor, "that he is not as fit to be president as I am, you will see how foolish this idea is."

VOA: special.2009.03.05

How foolish we were to imagine that national prosperity could be spun from figures on a computer screen, out of thin air.

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Abrahamson perhaps unwittingly revealed for all readers just how foolish was and is the widely held belief that the 2nd World War ended the Great Depression.

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It was only when things fell apart that I saw how foolish I had been and that it's simply not healthy to let the person you're with become your entire world.

CNN: STORY HIGHLIGHTS