一本好书是一个永远不会离开你的朋友。

When you are young, you think you will be happy when you are older. But then you get older and you realize you were happy when you were young.

人类社会生活的行为流是由存在的物质条件构成的。

农民增收不能只靠政策，更要靠市场机制和产业升级。

宣判死刑之人应当亲自行刑。

一个数学家的真正价值在于他们留下的问题。