They got this name from their political opponents, who charged that they were willing to burn down the barn to get rid of pro-slavery rats.

VOA: special.2009.03.05

I get charged one dollar for each mention of the class.

每提到一次这个课程，就得交费一美元。

哈佛公开课 - 计算机科学课程节选

- And we can think about why -- essentially we have fluorine and now we're adding another electron. So you can picture that fluorine is going to get larger in this case And that would be true for all of the negatively charged ions.

我们可以想一想这是为什么-,本质上来讲我们现在给氟原子加上了,另外一个电子,因此大家可以想象在这种情况下氟将变大,而且这对于其它负离子也是成立的。

麻省理工公开课 - 化学原理课程节选