If I'm saying something that you don't understand, the chances are pretty good that there's 25 or 50 other students in the class who don't understand it either.

如果我正说着什么你不懂的东西，那时就是举手的好机会,因为有25或50个别的学生,也不懂。

耶鲁公开课 - 死亡课程节选