Freedom is not merely the opportunity to do as one pleases; neither is it merely the opportunity to choose between set alternatives. Freedom is, first of all, the chance to formulate the available choices, to argue over them - and then, the opportunity to choose.

The essence of mathematics lies in its ability to reveal hidden patterns and structures in the universe.

形容时光飞逝，人生易老，鸡鸣和马蹄声象征着时间的流逝

我们所知道的很少，我们所不知道的却是无限的。