Development economics is ultimately about improving people's lives.

解释：本治则国家巩固，本乱则国家危亡。

The decay of political institutions is often a result of the inability to adapt to changing circumstances, leading to rigidity and eventual decline.

网球给了我一切，我想回馈一些东西。

Sustainable mining isn't an option anymore - it's our responsibility to future generations.

我对普通的不感兴趣，我对极端感兴趣。