你必须愿意失败才能成功。
使用程序证明四色定理不会改变数学-它只是表明该定理是一个世纪的挑战,对数学可能并不重要。
Every tree we plant today is a legacy for tomorrow.
I am the only person in the world I should like to know thoroughly; but I don’t see any chance of it just at present.