当你解决一个数学问题时，你不仅得到了答案，还理解了为什么这是答案。

The greatest human quest is to know what one must do in order to become a human being.

A people without children would face a hopeless future; a country without trees would face a future with even less hope.

人生最大的甜蜜是友谊。将其提升到最高享受的秘诀，只有少数人发现。