And the head you are seeing at the back there he was trying to touch is his wife's face.

他用手于去触摸的那个人,是他的妻子。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

Here we have two of our T.A.'s, actually these are the two head T.A.'s, and I want you to face forward so you don't see what I'm doing.

我们的两个助教在这里,事实上是两个助教主管,把脸朝前,不要看到我的动作

耶鲁公开课 - 博弈论课程节选