The beauty of a mathematical idea is that it can be shared and understood across cultures and time.
The stock market is filled with individuals who know the price of everything, but the value of nothing.
A philosophical problem has the form: "I don't know my way about."
树种多样性不仅仅是生态学,它是我们地球肺部的风险管理。
天下的道理,循环往复,所以能够永恒不息。