学习数学的最好方法就是做数学。
The best way to learn mathematics is to do mathematics.
Freedom is the recognition of necessity.
Loneliness is the poverty of self; solitude is the richness of self.
当天赋不努力时，勤奋会战胜天赋。
煤炭的可持续未来取决于我们能否在不牺牲依赖该行业的人的生计的情况下整合更清洁的做法。