The most difficult thing is to be simple.
In mathematics, the journey of discovery is often more rewarding than the destination itself.
The quality of an organization is determined by the quality of its systems.
协助儿童,能使你们之间建立起更亲密的关系。这胜过一般的感情,因为你不仅给他安慰,更给予了他们实际的帮助。
The world is full of obvious things which nobody by any chance ever observes.