If you don't have the units, then if you say the answer is 19, then we don't know what it means.

如果没有的话,比如你的答案是十九,那我们就不知道这是什么意思

耶鲁公开课 - 基础物理课程节选

And, although you think that nitrogen, I mean, it's an inert gas.

尽管你认为那是氮气，我的意思是，它是一种惰性气体。

麻省理工公开课 - 固态化学导论课程节选