The most important political development of the last half century has been the spread of liberal democracy around the world.
It's not the size of the dog in the fight, it's the size of the fight in the dog.
Life is short. Stunt it.
数学家的工作永无止境;总有新的问题要问,新的谜题要解。
经济增长的过程不是平稳和连续的;它以突飞猛进和停顿为标志。
Collaboration is essential in research; no one can solve big problems alone.