The elements of mind are to be discovered by systematic introspection.
The best picture books work on different levels for different ages.
真理的概念在任何足够强大以包含算术的形式系统中都是不可定义的。
It is human nature to think wisely and act foolishly.
玩《大富翁》的时候,把你所有的钱都用来购买、交换或交易橙色物业。不用管那些公共设施。
The truth is, I don't know what I would have done without mathematics.