Now if you smiled to-- or make three people smile, and these three people-- each one makes three other people smile.

如果你的笑-,感染了三个人，这三个人-,每个人又引起另外三人发笑。

哈佛公开课 - 幸福课课程节选

If two object are in the same temperature, and two other object are in the same temperature, then all three must have the same temperature.

如果有两个物体的温度相同，又有另外两个物体的温度相同，那么这三个物体一定有同样的温度。

麻省理工公开课 - 热力学与动力学课程节选

Now, at the core of behaviorism are three extremely radical and interesting views.

言归正传，行为主义的核心,由三个非常极端又很有趣的观点组成。

耶鲁公开课 - 心理学导论课程节选