Let's begin with a kind of warm-up sheet which we can anchor in these little drawings I've made.

让我们先来热一下身,看一下我在黑板上画的图。

耶鲁公开课 - 文学理论导论课程节选

And we talked about periodicity and properties, so let's go and take a look at what we have and see if we can reconcile this.

现在我们讲一下周期性，我们先看一下我们已经掌握的知识,看看能不能和我们要讲的达成一致。

麻省理工公开课 - 固态化学导论课程节选

So, let's first go with the attractive because you know this already.

我们先看一下引力的变化,因为你们已经知道这个了。

麻省理工公开课 - 固态化学导论课程节选