要成为一个好的数学家，你需要既有直觉又有严谨。
To be a good mathematician, you need to have both intuition and rigor.
The paper industry has a responsibility to lead the way in environmental stewardship.
成功来自于坚持和努力。
The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion.