The coal industry is not just about digging rocks; it's about powering progress and sustaining communities.
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.
The labor which it would require to make a single one of these guns by hand would exhaust the patience and perseverance of any ordinary workman.
优秀的数学家应该既严谨又富有想象力。