图片Fear is whispered in our ears and shouted in our faces. Faith must be fostered by the man or woman you see every day in the mirror. The former forever snaps at our heels and delays our course. The latter can spur our boot heels to be wandering, stimulate our creativity and drive us forward.

Happiness is rarely absent; it is we that know not of its presence.

用程序证明四色定理不会改变数学——它只是证明了这个挑战了一个世纪的定理是一个有限的问题。

在黑暗中，我们学会珍惜光明。