And I want to share with you couple of studies-- I'll share one study and then another later-- about the environment.

我想介绍两个研究-,先说第一个再说第二个，关于环境。

哈佛公开课 - 幸福课课程节选

I'll just mention--I want to mention a couple other institutions that are very important in real estate and those are Fannie and Freddie.

我想介绍一下,在房地产行业中非常重要的,两个机构,房利美和房地美

耶鲁公开课 - 金融市场课程节选

But let me say two things now, after having said that.

说完那一点之后,现在我要介绍两个理论

耶鲁公开课 - 欧洲文明课程节选

I'm going to introduce two very special vectors.

接下来我要介绍两个非常重要的矢量

耶鲁公开课 - 基础物理课程节选