除非我了解业务，否则我从不购买股票。

切割金属艺术的第一步是找到一个具备必要技能和经验的人来做这项工作。

You can't live a positive life with a negative mind.

"To write about love is to write about humanity in its most vulnerable and powerful form."

数学的快乐来自创造的行为，而不仅仅是结果。