Mathematics is the art of giving the same name to different things.
The secret of change is to focus all your energy not on fighting the old, but on building the new.
再多一点坚持，再多一点努力，看似无望的失败可能会变成辉煌的成功。
任何需要手册才能工作的产品都是坏的。
"No one can build you the bridge on which you, and only you, must cross the river of life."