老师正在讲课，爱丽丝打起瞌睡来了。

Alice dozed off while her teacher was talking.

youdao

当我正在讲课的时候，他打断了我。

When I was giving a lecture, he interposed me.

youdao

老师正在讲课，彼得打起瞌睡来了。

Peter dozed off while his teacher was talking.

youdao

So it's really neat to think that your counterparts 100 years ago right here at MIT could have been sitting in a class where they had Lewis as their lecturer, and he's putting forth these ideas -- these are actually his lecture notes, even though it wasn't even published yet, and giving this idea of Lewis structure, which is exactly what we keep using today in order to make a lot of these predictions.

因此会有很棒的感觉，当想一想一百年以前像你们一样,在这上学的同学可能正坐在教室里,听路易斯讲课，而他正在提出这些想法-,-而这些正是他的课堂讲义，尽管当时还没有发表，但已经给出了路易斯结构的思想，这正是我们直到今天都一直在用的,用它来做很多预测。

麻省理工公开课 - 化学原理课程节选