—— 请按键盘 空白键 开始游戏 ——

我不能教会别人任何事。我只能让他们思考。
I don't think that everyone should become a mathematician, but I do believe that many students don't give mathematics a real chance.
Function precedes form in the evolution of mental processes.
A person may cause evil to others not only by his actions but by his inaction, and in either case, he is justly accountable to them for the injury.