Within 20 degrees of separation from you initial smile to the three people, the entire world will be smiling.

只需要20度的分隔,从你用笑容感染三个人开始，全世界就会笑起来。

哈佛公开课 - 幸福课课程节选

Even though we have a noun, the smile, that if you're not careful might lull you into thinking there must be a thing, the smile.

即使我们有笑容这个名词,如果你不够谨慎,可能会想当然地认为,一定存在着笑容这一事物

耶鲁公开课 - 死亡课程节选

And those nine people make three-- each one-- three other people smile.

那九个人-,每个人再用笑容感染三个人。

哈佛公开课 - 幸福课课程节选

Look at his smile, really more of a smirk.

看着他的笑容，那根本就是在奸笑。

耶鲁公开课 - 政治哲学导论课程节选

It is a smile.

给它一个笑容。

耶鲁公开课 - 死亡课程节选