如果我们想要清洁的空气和水，就必须从保护森林开始。

生活中的唯一限制是你为自己设定的限制。

Ethical business practices are not constraints, but foundations for long-term growth.

"The only way to learn mathematics is to do mathematics."

Life is like music。It must be composed by ear，feeling and instinct，not by rule.

地理学的研究是对地球作为人类居住地的研究。