真正的美国发现还在我们面前。我们精神、我们人民、我们强大而不朽的土地的真正实现，尚未到来。

学习数学的唯一方法就是做数学。

Money and art are not opposites.

The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.

The human being is always more than what he knows of himself.

发球是网球中最重要的一击。