So we can think about something I mentioned last time, which is when we're thinking about chemistry and what's really interesting in terms of chemical reactions, it's mostly valence electrons we're talking about, those are the ones that tend to be involved in chemical reactions.

我们可以考虑一下我上次提到过的一件事，那就是如果我们讨论化学,以及什么是化学反应中,真正令人感兴趣的东西，我们讨论的几乎都是价电子，它们才是在化学反应中,真正起作用的部分。

麻省理工公开课 - 化学原理课程节选

It depends on the class, like, organic chemistry, for instance, is always open book, open notes.

这要看是什么科目，例如说有机化学总是开卷考试，可以看笔记。

考试应该这么准备 - SpeakingMax英语口语达人

What is it when you run a chemical reaction under ordinary circumstances, what's constant?

如果你在通常的环境下进行化学实验,那么这些条件是什么？什么保持常数？

麻省理工公开课 - 热力学与动力学课程节选

some chemistry class will show up in here, and someone will wonder what that is, and Barth will have done his work, or we will have done Barth's work for him. Now, let me ask you another question. Who is the narrator of "Night-Sea Journey"?

这里将会上化学课，有人会想,这到底是什么，巴斯将完成他的工作，或是我们将为他完成工作，现在，我来问你们第二个问题，《夜航》的叙述者是谁？

耶鲁公开课 - 1945年后的美国小说课程节选