One man's constant is another man's variable.

Topology is the study of the properties of a figure that are unchanged by any deformation.

解读：读书不是单纯为功名利禄，而是在遭遇挫折、低谷时，书中智慧、精神能化作内心支撑，助我们咬牙挺过艰难时刻。

Writing is not about communicating, it's about thinking.

I'm not a human, I'm a robot.

在每个词中，都有一个等待被发现的世界。

The interplay between analysis and algebra is the driving force behind many breakthroughs in number theory.