When you get--this is Rituparna, counting the leaves on a tree-- you can estimate, from a sample, the population expected values.

如果你...像数叶子的睿都巴若那一样,只有部分样本的话,你可以来估计总体均值

耶鲁公开课 - 金融市场课程节选

We'll get to oxidation number in the second half of this course, but it's not in any way the same idea as formal charge.

我们会在课程的后半部分讲到氧化数，但它和形式电荷完全不是同一个概念。

麻省理工公开课 - 化学原理课程节选