And if you remember this phrase, I don't know why you would, but this will help you learn the lanthanides in order.

如果你能记得这句话的话，我不管你们是怎么做到的，但是这个确实会帮助你按顺序记住镧系元素。

麻省理工公开课 - 固态化学导论课程节选

OK, to work. A word of warning: fasten your seat belts.

好了，开始工作，一些警告的话：,系紧你们的安全带。

麻省理工公开课 - 计算机科学及编程导论课程节选

You don't need to know those, but just because it's a special case with the hydrogen atom, they do tend to be named -- the most important, of course, tends to be the Balmer series because that's what we can actually see being emitted from the hydrogen atom.

你们不需要记住,但因为这是氢原子的特例,人们想要命名它，最重要的是当然是Balmer系,因为它是我们可以看到的,从氢原子放出来的光谱。

麻省理工公开课 - 化学原理课程节选