The rule of the three Rs, reduce, reuse, recycle.

三 R 原则，减少、重复使用、回收。

In the new economy, computer science isn't an optional skill-it's a basic skill, right along with the three “Rs.”

在新经济环境下，计算机科学不再是一项可选技能，而是与3R（阅读、写作、算术）一样成为一项基本技能。