And though it may sound incredible, your body actually contains about a teaspoon's worth of this stuff formed thirteen billion years ago by the very first stars."

VOA: special.2010.09.29

It decreases. If you're still not completely up on the periodic trends, that is stuff that's going to be on the first exam, so make sure that you're able to do this without taking too much time to think about it.

它会降低，如果你还没有完全掌握周期性规律，而这是第一次考试要求的内容，因此请务必做到不用,想太久就能做到这点。

麻省理工公开课 - 化学原理课程节选

Again, pset one will walk you through this and you'll get familiar with this stuff, even though it looks a little arcane at first glance.

此外，习题集1将带你通过这个,你将熟悉这些东西，即使第一眼它看起来是比较晦涩的。

哈佛公开课 - 计算机科学课程节选

The first crowd to do stuff like that, you will find, in the fifth century B.C. In Greece is a movement called the Sophistic Movement.

你们会发现第一批做这种事情的人,是在公元后五世纪的希腊人,当时兴起了一种叫诡辩的运动

耶鲁公开课 - 古希腊历史简介课程节选