Farmers are the first environmentalists, working with nature every day.

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.

Mathematics is not a spectator sport. You have to get involved.

每首歌都有一个故事，而我的工作就是让这个故事鲜活起来。

勤于学习的人才会愿意施教。