So even though we see a nodal plane down the center, I just want to really point out that it's only when we have a nodal plane in the internuclear or the bond axis that we're calling that a pi orbital.

虽然在中间有个节面，我想要指出的是,只有节面在核间轴,或者键轴上时,我们才叫它π轨道。

麻省理工公开课 - 化学原理课程节选

I need you tear not the page out; I need you to tear this phone book in half in front of 500 of your peers.

我不是要你仅仅撕下来那一页;,我要你当着500位同学的面,把整个电话薄撕成两半。

哈佛公开课 - 计算机科学课程节选