对逻辑形式的研究不仅关乎语言，也关乎世界。

When you are young, you think that the world is a place where you can live as you choose. But as you get older, you realize that the world is a place where you have to live as you must.

你越是否认某件事，它就会引起越多的关注。

Development economics is ultimately about improving people's lives.

真正的领导力在于服务他人，而非指挥他们。