What was neat about it is before that time, the predominant species to use for air conditioning or refrigeration was ammonia.

在这之前是很整洁的，之前最主要的用于空调或者冰箱的,物质是氨。

麻省理工公开课 - 固态化学导论课程节选

And we haven't seen all of these sorts, but it's actually quite neat to recognize how different the underlying work is of each of these algorithms.

我们还没有探讨所有的排序算法，但应该很容易区分,每一种算法其内在的,不同之处。

哈佛公开课 - 计算机科学课程节选