Now this is a good place to start, because we are very familiar with ionization energy, we've been talking about it it's that minimum energy required to remove an electron from an atom.

现在这是一个开始下面内容的好地方，因为我们已经很熟悉电离能了，我们从很久以前就一直在讨论,它是从一个原子中,拿走一个电子所需要消耗的最低能量。

麻省理工公开课 - 化学原理课程节选

So, give me two more minutes, I'm going to end, and a few of you, faces, I've heard this before, people that I know; but, I guess one reason why I'm in history--well, because I read a book a long time ago.

所以,再给我两分钟,我就要结束了,你们有些人,面孔,这我见过,有的人我认识,但是,我觉得我之所以搞历史,因为我很久以前读过一本书

耶鲁公开课 - 1871年后的法国课程节选