That's all you have to be careful about.

你们一定要对此多加小心

耶鲁公开课 - 基础物理课程节选

Anyway, you have to be careful with your motorcycle and always wear your helmet.

不管怎么说，你都要小心骑摩托车，记得一定要带着头盔。

I didn't 实战 - SpeakingMax英语口语达人

But because we're now programming a computer at a lower level and because as we said last week, you really have to be precise and then careful to instruct this machine, this fairly dumb machine that will only do what you tell it to do very specific instructions, do we have to use a more precise syntax than just a puzzle piece might have previously allowed.

但是我们是要在电脑的低平台上编程不是吗？,那我们就要像我上周提到过的那样，一定要小心，小心，再小心地,操纵这台又聋又哑的机器,它只会根据你敲进去的,特定指令来做事，所以我们必须使用非常精细的语法,而不是模模糊糊，让人费解的概念。

哈佛公开课 - 计算机科学课程节选