She wanted to say something, but then thought better of it.

她想说些什么，后来又觉得还是不说为好。

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He thought about giving up his job, but then common sense reasserted itself.

他曾想放弃这份工作，但后来还是理智占了上风。

《牛津词典》

At first I thought he was shy, but then I discovered he was just not interested in other people.

起先我以为他腼腆，后来才发现他对别人没兴趣。

《牛津词典》

Here is a reading of his description of his first sight of the bats and the big cave: "I thought it was a volcano, but then,I'd never seen a volcano nor never before had I seen bats swarm, for that matter.

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They thought they had the system solved, but then they had a bank run last year.

他们认为已经系统性解决了挤兑问题,但去年却又出现了银行挤兑

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But then I thought about it.

但我仔细想了一下。

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But then I thought maybe he should check his eyes, go back to square one and look at his technique.

BBC: Vaughan's resignation shocks game

But then I thought: what if I just stop refreshing that page?

FORBES: I Don't Care if You Read This Article

But then he thought better of it, and howled again.

NEWYORKER: Max at Sea