Mathematics is not a spectator sport; you have to play to understand.
解释:把腹心的疾病去掉,而放在大腿胳臂上,有什么益处?
I'm not afraid of dying, I'm afraid of not trying.
Three grand essentials to happiness in this life are something to do, something to love, and something to hope for.
"Words are the only things that last forever; everything else perishes."