定理是永恒的;它们的证明是短暂的。
The act of writing is an act of discovery.
Psychological truth is what works in the practical world.
The best thing you can do is just be yourself and have fun.
健康的森林意味着健康的经济;两者密不可分。
这就是学习的意义。你突然以一种新的方式理解了你一生都理解的东西。