There was a lot of physics going on, but we didn't know a whole lot about atomic structure back in those days.

物理学在迅速发展，但在这之前并没有人对,原子结构有很全面的了解。

麻省理工公开课 - 固态化学导论课程节选

He wants you to finish everything by tomorrow, but you think it's impossible.

他想让你在明天之前把所有事都做完，但你觉得这肯定是不可能的。

How can I 课堂 - SpeakingMax英语口语达人

Welles heard that obviously, and he quickly came back. But when she died, he stopped taking lessons, before that, he was adept before he was ten years old.

威尔斯当然听到了，所以他,很快回来了，但在,他母亲去世之后，他就不再上课了，在这之前，在他十岁的时候他就对乐器很熟练了。

麻省理工公开课 - 电影哲学课程节选

I think I might want to take it down before he comes.

但在他来之前我得把这篇文章撤掉

耶鲁公开课 - 金融市场课程节选

But before I do that, I would also like to welcome-- I know that some of you are watching this from home, to the extension school students, it's wonderful to have you here.

但在这之前，我也想对-,我知道你们中的有些人正在家里看这堂课，对进修学校的同学们表示欢迎，很高兴你们能听我的课。

哈佛公开课 - 幸福课课程节选

And in a moment, I'll ask whether it's the best possible explanation, but before we do turn to that question, there is an objection to this entire way of looking at things that's probably worth pausing for a moment and considering.

而马上,我要问你们这是否是最好的解释,但在我们转向那个问题之前,有一个对这一整套,看待问题的方式的反驳,或许值得我们稍微停留并考虑一番

耶鲁公开课 - 死亡课程节选

psi So we're going to for psi, and before that, we're going to figure out that instead of n just that one quantum number n, we're going to have a few other quantum numbers that fall out of solving the Schrodinger equation for what psi is.

我们要讲到，但在这之前，我们已经知道了,主量子数，现在我们需要知道，其他一些,解psi的薛定谔方程,所需要的量子数。

麻省理工公开课 - 化学原理课程节选

But before you even do that, I want to define for you an important concept, which is the velocity at a given time, v .

但在这之前,我要给你们定义一个重要的概念,也就是给定时刻的瞬时速度v

耶鲁公开课 - 基础物理课程节选