Aristotle, in his Politics of course, tells us the most on this subject and often he is our source of information.

亚里士多德,在他的《政治学》中,告诉我们很多有关这个主题的知识,他经常也是我们信息的来源

耶鲁公开课 - 古希腊历史简介课程节选

So let's turn our attention to a new topic, which is thinking a little bit about the periodic table, and also talking about periodic trends.

我们的新主题上，我们将会讨论一点关于元素周期表的知识，同时也会讲一讲周期性规律。

麻省理工公开课 - 化学原理课程节选