经济周期不仅仅是围绕某个平滑趋势的波动，而是经济受到根本性冲击的结果。

It took untold generations to get you where you are. A little gratitude might be in order. If you're going to insist on bending the world to your way, you better have your reasons.

数学家的工作永无止境；总有更多的问题需要解决。

It is not what we believe, but why we believe it; moral responsibility begins there.  

Quality should never be compromised for the sake of speed.

"A picture book is like a small theater."

Mathematics is a living subject, constantly evolving and growing.

我们不做市场调查。我们只做我们相信的东西。