But what's interesting with these cases is you couldn't have predicted ahead of time that they would be heroes.

但这些例子所表明的就是,你不可能提前预知,他们会成为英雄

耶鲁公开课 - 心理学导论课程节选

Your final exam will be basically one or two questions that I'll give to you ahead of time.

你们的期末论文要讨论1到2个问题,我会提前给你们的。

耶鲁公开课 - 新约课程节选

But I want to warn everybody ahead of time, I will not be following the textbook.

不过我先提个醒,我不会完全参照课本

耶鲁公开课 - 博弈论课程节选