一个人懒惰又奢侈，生活就会贫困；勤劳而节俭，生活就会富足。

Fashion is a form of imitation and so of social equalization, but, paradoxically, in changing incessantly, it differentiates one time from another and one social stratum from another.

Mathematics is not a spectator sport.

煤炭行业必须进化，否则就有被淘汰的风险。适应是生存的关键。