Mathematics knows no races or geographic boundaries; for mathematics, the cultural world is one country.
追求数学知识是一场永无止境的冒险,充满了挑战、惊喜和解决不可解问题的满足感。
Every word is a world.
The only fence against the world is a thorough knowledge of it.
The real challenge is not in solving the equations, but in understanding what the solutions mean.