He really must be careful about thinking aloud. Who knew what he might say?

他真地得对自言自语小心点。谁知道他可能会说什么？

《柯林斯英汉双解大词典》

You should be careful about how to talk with them.

你应该要注意与他们交谈的方式。

youdao

A boy might be careful about sharing his feelings with his close friends.

一个男孩可能会对与他的密友分享其感受小心翼翼。

youdao

And be careful about stalagmites you might trip over one on the floor.

VOA: special.2009.12.07

So it's a way of reminding you, I've got to be careful about the types of things that I put in.

因此我这是在提醒你，一定要对输入的东西的类型,多加注意。

麻省理工公开课 - 计算机科学及编程导论课程节选

Then there are other people who are pretty careful about what they eat and they're still prone to gaining weight.

还有一类人非常注意控制饮食,但是仍然容易发胖

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If you do leave one employer for another, above all, be especially careful about dealing with former customers.

FORBES: Whose Rolodex is it, anyway?

The embassy is warning Americans in France to be careful about speaking English on the streets.

CNN: Attacks spark global red alert

"I think we have got to be very careful about anything like this, " he said.

BBC: Norfolk PCC Stephen Bett: 'Scrap some speed limits'