So if I try to rotate my 2 atoms, you see that I have to break that pi bond, because they need to be lined up so that the electron density can overlap.

如果我要试着转动两个原子，你会看到我必须要打破一个π键，因为他们需要连接起来,让那些电子能够重叠。

麻省理工公开课 - 化学原理课程节选

Get right behind that guy; you got to be--boy you got to be lined up.

到那个伙计后面去,现在排好队,同学,排好了

耶鲁公开课 - 古希腊历史简介课程节选