A proof is a device for convincing someone else that a mathematical statement is true.
Survival can be summed up in three words – never give up. That’s the heart of it really. Just keep trying.
The best time to plant a tree was twenty years ago. The second best time is now.
预测未来的最好方法就是创造未来。
We must be vigilant in protecting the Internet from those who would misuse it.