He says young entrepreneurs a unique opportunity to make a profit while making a difference for communities around the world.

VOA: standard.2009.12.04

Then this moving this around here, and it will give us a sense of the difference in style between pop music and classical music.

两种音乐重叠回旋着,这让我们一下子感受到了,音乐中古典与流行的反差

耶鲁公开课 - 聆听音乐课程节选

So that's just a little bit of a check for yourself, and it should make sense because what you're doing is you're calculating the difference between energy levels, so you just need to flip around which you put first to end up with a positive number here, and that's a little bit of a check that you can do what yourself.

所以你们总要确保括号，离得这项是正的，这是你们自己,可以做的检查，这事很有道理的，因为你们做的是计算能量差,所以你需要调整顺序来保证一个正数，这是你们自己可以做的检查。

麻省理工公开课 - 化学原理课程节选

You have to step up. You have to serve." He said groups like the Clinton Global Initiative are making a difference around the world by working with business to cut dangerous emissions, empowering entrepreneurs with micro-loans, and giving hope to some of the world's poorest children.

VOA: standard.2009.09.23

The difference is around the eyes.

不同之处在于眼睛。

耶鲁公开课 - 心理学导论课程节选