Step three in our Lewis structure rules is to figure out how many electrons we would need in order for every single atom in our molecule to have a full valence shell.

路易斯结构规则的第三步是,找出让分子中每个原子的价壳层,都排满应该需要多少个价电子。

麻省理工公开课 - 化学原理课程节选

hey'd rather single step it through using Idol or something, than just read it and try and figure things out. The most important thing to remember when you're doing all of this is to be systematic.

比起阅读代码发现错误来他们,宁愿用内置的操作层,或者其他工具一步完成,你要记住的最重要的事情,就是要系统化的去做调试。

麻省理工公开课 - 计算机科学及编程导论课程节选