The land is the real client, not the person who pays the fee.

我还活着，我有机会用我的生命做些事情。这就是我需要的唯一动力。

The fundamental impulse that sets and keeps the capitalist engine in motion comes from the new consumers' goods, the new methods of production or transportation, the new markets, the new forms of industrial organization that capitalist enterprise creates.

我从不买任何东西，除非我能给自己一个充分的理由为什么要买它。

数学的目标是理解我们观察到的现象背后的结构。

Sustainability isn't an option; it's a necessity for the future of energy.