经济景观是一个由不同等级的中心地组成的系统，每个中心地为特定区域服务。

"The world breaks everyone, and afterward, many are strong at the broken places."

Reading furnishes the mind only with materials of knowledge; it is thinking that makes what we read ours.

成功不是幸福的关键。幸福是成功的关键。如果你热爱你所做的事情，你就会成功。

The only way you can write the truth is to assume that what you set down will never be read.

Coal mining is a partnership between the earth and human ingenuity.

思想和背景的多样性推动创新，要拥抱它。