How long do you have to be around a person to see him, to estimate how good a lecturer that person is?

你要看一个人多久，才能评估出他讲课有多好？

耶鲁公开课 - 心理学导论课程节选

to be killed in a plane accident this weekend and there was a guest lecturer for you on Tuesday there'll be somebody alive lecturing to you.

我周末死于空难,而下星期二又有客座教授的话,就会有人活着给你们上课。

耶鲁公开课 - 死亡课程节选