Thirty-nine-year-old Mr.Hariri says he faced "impossible conditions" in selecting a Cabinet lineup.

VOA: standard.2009.09.11

So, in this one we're selecting the correct electronic configuration for an ion.

那么，这次我们要做的是,选出一个离子正确的电子排布。

麻省理工公开课 - 化学原理课程节选