In fact,if I keep talking, soon enough you will start to think I am an old hat about this -- a real expert.

VOA: special.2010.05.09

Whenever you hear the term ionization energy, make sure you keep in mind that unless we say otherwise, we're talking about that first ionization energy.

但无论什么时候你听到电离能这个词，一定要记得，除非特别说明，我们都是在说第一电离能。

麻省理工公开课 - 化学原理课程节选

So just keep in mind, like we're talking about with the student, you can't be afraid of making mistakes

所以记住，就像我们对学生说的，你不能害怕犯错误，

生存英语 - SpeakingMax英语口语达人

Now, ask yourself this, especially if you're talking about Greeks, are they going to keep shelling out money for an oracle that gives them answers that turn out to be wrong? No.

现在想想这个,尤其说到古希腊人,为了得到神谕,他们会不停地破费,而这些神谕最后还是错的吗,当然不会

耶鲁公开课 - 古希腊历史简介课程节选

It's kind of ironic that we put this in the same lecture as we talk about atomic radii, which we also call r, but they're two different r's, so you need to keep them separated in terms of what you're talking about.

有点讽刺的是,我们在同一堂课里还讨论过了原子半径，它也是用，r，表示的，但是它们具有不同的意义，因此大家需要注意区分它们,弄清楚我们讨论的是哪一个。

麻省理工公开课 - 化学原理课程节选