数学不是一项观赏性运动。你必须亲自去做才能理解它。
Success comes when you focus on solving problems, not just making profits.
It seems to me that if you or I must choose between two courses of thought or action, we should remember our dying and try so to live that our death brings no pleasure to the world.
A first sign of the beginning of understanding is the wish to die.
Oh,to struggle against great odds,to meet enemies undaunted.