So, if you can't immediately know, and you don't all have periodic tables in front of you, so that's fine, but if you have a periodic table in front of you, you need to be able to count valence electrons, so work on that if it doesn't come naturally to you in terms of figuring that out.

如果你不能马上想到，而且你手上没有周期表，那还好，但如果你面前有一张周期表，那你就得具备从中查出价电子个数的能力，如果你不能自然而然地想到,请在这方面多下点功夫。

麻省理工公开课 - 化学原理课程节选

So, a part of you wants to become the greatest whatever it is that you want to become and you wouldn't be here if you weren't very competitive and very eager to come out first, devoted to arete and your own version of that kind of thing.

所以 你的一部分意识想变成最伟大的人,不论你想要在哪个领域变得伟大,而且如果你没有竞争力,或不是一直争取第一,那你也不会坐在这里,力图更上一层楼,以穷千里目

耶鲁公开课 - 古希腊历史简介课程节选