And I get down to a certain card and I am stumped, so I will leave a space waiting for that card to appear on cue.

我遇到某张牌,会被困住，我会留些地方给,恰好要出现的牌。

麻省理工公开课 - 固态化学导论课程节选

So if you go to your website today, you will find I've assigned some problems and you should try to do them.

如果你浏览你们的个人页面的话,你会发现一些我给你们留的作业,请你们努力完成

耶鲁公开课 - 基础物理课程节选

Finally I want to oppose a challenge to you and ask you a question.

最后我想挑战一下你们,给你们留个问题。

麻省理工公开课 - 媒体、教育、市场课程节选