For those of you just walking in now, you might not have a chance to get all of the thought process that you need in on this clicker question, because it is based on a Lewis structure, so we will go over it.

那些刚刚进来的同学，你们可能没有机会时间来回答,因为答案是基于Lewis结构上的,所以我们赶紧看一下。

麻省理工公开课 - 化学原理课程节选