想象一下，你的面前有一个大圆柱，希望大家可以想象到，其法向量总是水平的。

If you imagine that you have this big cylindrical type in front of you, hopefully you can see that a normal vector is going to always be horizontal.

youdao

想象一下假如超过半数的购物者都买同一件衣服，我们大家都得穿这样的衣服，那么我现在就会正穿着露脐装，因为超过半数的购物者会是十几岁的女孩。

Imagine if our clothes were selected by the majority of shoppers, which would be teenage girls. I\'d be standing here with my bellybutton exposed.

youdao

再想象一下假如大家的菜谱由家庭无记名投票决定，由于我有三个孩子和三条狗，那么大家就可能会正吃着圈圈饼和烂肉。

Imagine deciding the dinner menu by family secret ballot. I\'ve got three kids and three dogs in my family.

youdao

And this is really interesting to think about because you can imagine in our body we have concentrations of all types of ions, and specifically, some seem very, very similar to each other.

这是非常令人感兴趣的,因为大家可以想象一下，在我们的体内我们有,一定浓度的任何类型的离子，而且特别地，其中有一些非常非常地相似。

麻省理工公开课 - 化学原理课程节选

That's the huge force that we're talking about in terms of making a bond stable, but there are also repulsive forces, so you can imagine we're going to have electron-electron repulsion between the two electrons if we're bringing them closer together.

正是这个非常强的力,使得我们所讨论的这个键能够稳定存在，但是其中还有排斥力存在，大家可以想象一下,我们会有电子与电子之间的排斥力,如果让它们离得更近。

麻省理工公开课 - 化学原理课程节选