Early in 2011, the world price of copper reached a record high of over $10 000 per tonne. Two events appeared to lie behind this high price. First, China's rapid economic growth and the massive building of infrastructure. Second, an explosion closed a major Chilean port used for shipping a substantial fraction of the world's copper output. Use a demand-and-supply diagram to illustrate these events in the copper market, and explain how each event shifts either the demand curve or the supply curve.