不如意的事要能排遣，日子清苦要能守得住，无道理的事要受得住，愤怒产生时要忍耐，欲望产生时要克制。
You don't have to understand life. You just have to live it.
The challenge of our time is to harness energy without harming the planet.
"To be a spy is to live in a world of constant doubt and suspicion."
The greatest question of our time is not communism versus individualism, not Europe versus America, not even the East versus the West; it is whether man can bear to live without God.
学习数学的唯一方法就是做数学。