Cleveland warned that it would be far better to make safe,careful, and intelligent changes in the tariff laws now.

VOA: special.2010.05.20

I'm an immigrant: better be careful.

我是移民,所以我要小心点才行

耶鲁公开课 - 博弈论课程节选

You'd better be careful.

你最好小心点。

I'd better 实战 - SpeakingMax英语口语达人

I declare a variable called n. I'm not giving it a value yet, so I had better be careful.

我申明一个变量n，我先不给它赋值，所以我最好小心点。

哈佛公开课 - 计算机科学课程节选