To see the nature of the problem you've got to think about the fact that it's a combination package.

要看到问题的本质,你必须考虑到这是一个组合的事实。

耶鲁公开课 - 死亡课程节选

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

You have to remain celibate and, as we will see in the coming week, this is important to Milton. You have to remain sober, and you must eat vegetarian .

你必须独自生活，我们会在下周看到，这对弥尔顿很重要，你必须保持冷静，你还必须吃素。

耶鲁公开课 - 弥尔顿课程节选