This should all sound incredibly familiar, like I'm just repeating myself in terms of photoelectric effect, because essentially that's what I'm doing, and that's one reason we spent so much time and did so many problem-set problems on the photoelectric effect.

这应该听起来极其熟悉，就像我在重复自己在讲光电效应时所说的话，因为基本上我正是在这样做，这也是我们在光电效应这个问题上,花这么多时间,做这么多习题的原因之一。

麻省理工公开课 - 化学原理课程节选

So if you get the CD set, not only do you get a wonderful beginning library of classical music but in effect you get a lifetime service contract with it.

所以一旦你买了整套CD,你不仅可以拥有一个古典乐图书馆,而且还可以享受终身服务

耶鲁公开课 - 聆听音乐课程节选