No man is useless in this world who lightens the burden of someone else.

"The essence of mathematics is not to make simple things complicated, but to make complicated things simple."

阳光不会永远照耀，但只要它还在，我们不妨一起闪耀。

书籍是想象力的种子。

摆脱诱惑的唯一方法就是屈服于它。