主要的义务规则是那些要求或禁止某些行为的规则。
The problem is not that people are taxed too little, the problem is that government spends too much.
The causal framework is the foundation of scientific reasoning.
学到的不是动作,而是意义。
The future of forestry lies in technology, but it must serve nature, not exploit it.
教育的回报太遥远,而今天的生计太紧迫。
I believe in the power of cinema to change the world.