Understanding controllers boils down to the three rs: return, redirect, and render.

对控制器的理解可以归结为三个r： return、redirect和render。

youdao

Commoners received a more basic, “three Rs” type of schooling, and usually had to pay for it.

平民只接受最基本的教育，类似于“尊重自我尊重他人对所有行为负责”这类的教育，而且通常还要自己付学费。

youdao

Follow the three rs: respect for self, respect for others and responsibility for all your actions.

遵行三个原则：尊敬自己、尊敬别人、为自己的行为负责。

youdao

The children also get a lesson in two of the three Rs (reduce, reuse, recycle).

CNN: Envisioning a world without garbage

The government now wants a return to greater emphasis on the three Rs.

ECONOMIST: South Africa's education system

And Cafu believes that Brazil's 'Three Rs' attack of Ronaldo, Rivaldo and Ronaldinho can stretch the English rearguard to breaking point.

BBC: Cafu praises England