乐观主义者认为这是所有可能世界中最好的一个。悲观主义者则担心这是真的。
数学是一门活生生的学科,随着新的思想和发现不断演变。
Darkness cannot drive out darkness: only light can do that. Hate cannot drive out hate: only love can do that.
We are all in the gutter, but some of us are looking at the stars.
Appreciate everything your associates do for the business. Nothing else can quite substitute for a few well-chosen, well-timed, sincere words of praise. They're absolutely free and worth a fortune.