You know that buying gold coins from some newspaper ad is not a smart investment, but they know that there will be people out there.

你们明白购买报纸广告上宣传的金币,是一种不明智的投资选择,但销售商知道总会有人上钩

耶鲁公开课 - 金融市场课程节选

But if you're not smart about it, things can happen.

但如果你不够聪明，就会出事了。

大城市是否危险？ - SpeakingMax英语口语达人

That means if you're good looking you'll also be smart but from him that hath not shall be taken away even that which he hath.

也就是说如果你长得好看,你也会更聪明，但“没有的，连他所有的,也要夺过来“

耶鲁公开课 - 心理学导论课程节选