As every time we introduce a new programming concept, we'll relate it back, as we have been doing consistently, to defensive programming.

我们每次介绍一个,新的编程概念的时候，就会和以前讲的联系起来，就和我们介绍防卫性程序设计一样。

麻省理工公开课 - 计算机科学及编程导论课程节选

We have a concept of time going forward in a particular way.

我们有着时间以特定方式,向前流动的概念。

麻省理工公开课 - 热力学与动力学课程节选