All right. So, today we're going to be talking about molecular orbital theory, but first I wanted to just mention, in case some of you didn't hear what the Nobel Prize was this morning, and this was in chemistry, it went to three different chemists.

好的，今天我们要讲的是,分子轨道理论，但首先我要说，以免有些同学没有听到,今天早上的诺贝尔奖，这是化学奖，它颁给了3个不同的化学家。

麻省理工公开课 - 化学原理课程节选

So, for example, we have this average level, and then it can go high where we have the peak, or it can go very low. We can also discuss sound waves, so again it's just the periodic variation of some property -- in this case we're talking about density, so we have high density areas and low density areas.

例如这是平均位置，在峰的位置水位高，在谷水位低，我们也可以,讨论声波它也是某种,量的周期变化，在这里我们,讨论的是密度,我们有高密度区和低密度区。

麻省理工公开课 - 化学原理课程节选

We have to know what to pay attention to People who are not good in focusing their attention on the right things -I'm not just talking about attention deficit disorder, I'm talking about some more high-level question of how you know what you should be paying attention to.

我们需要知道哪些值得注意,那些主次不分的人,我谈论的不仅是注意力不足过动症,还有在面对复杂问题时,你如何知道哪些事情值得关注

耶鲁公开课 - 金融市场课程节选