主要的义务规则是那些要求或禁止某些行为的规则。

Sustainable infrastructure should balance economic, social and environmental benefits.

The only thing more painful than being an active forgetter is to be an inert rememberer.

The decisions of the poor are often heartbreakingly rational.

“怜悯或同情，是所有人同样自然的情感。”

金钱不是激励因素。我的动力来自玩我喜欢的游戏。