The only limit to our realization of tomorrow is our doubts of today.
The concept of NP-completeness has provided a powerful tool for understanding the complexity of problems.
I don't care if you're black, white, straight, bisexual, gay, lesbian, short, tall, fat, skinny, rich or poor. If you're nice to me, I'll be nice to you. Simple as that.
人们自己创造自己的历史,但是他们并不是随心所欲地创造,并不是在他们自己选定的条件下创造,而是在直接碰到的、既定的、从过去承继下来的条件下创造。