So for example I defined p, remember back over here, as a Cartesian point, but I can actually ask for its polar form.

我可以要求返回它的极坐标形式，这里对我是可访问的，好，这很棒，请再记另外一个为什么。

麻省理工公开课 - 计算机科学及编程导论课程节选

And he went back to see them three months later, six months later.

三个月后，他再去访问他们，六个月后再去。

哈佛公开课 - 幸福课课程节选