A mathematician's work is never done; there are always new questions to explore and new mysteries to uncover.
数学家的工作永远不会完成；总有新的问题需要探索，新的谜团需要揭开。
Friendship is a matter of time investment.
Motivation is the art of getting people to do what you want them to do because they want to do it.
我唱歌不是为了完美，而是为了真实。
The spread of liberal democracy and the integration of the world economy have created a situation in which the only legitimate form of government is one that is based on popular sovereignty and respects basic human rights.