No one is altogether to be blamed for the defects of his nature; but he is blameworthy if he takes no pains to correct them.
每一刻都是新的开始。
里氏替换原则是面向对象编程中的一个基本概念,确保派生类可以替代其基类使用,而不会改变程序的正确性。
I believe in being strong when everything seems to be going wrong.
"There is no substitute for books in the life of a child."