【正确答案】 C

【答案解析】[解析] The Worldwatch Institute predicts that by 2050 an additional three billion people will be competing for already limited water resources. India already has an estimated annual water deficit of 3786 billion cubic feet per year, and is projected to and another 519 million people by 2050. China, already facing a 1071 billion cubic feet water dificit, is projected to add close to 200 million people to its population. "In these and other water-short countries," says Lester Brown of the Worldwatch Institute, "population growth is sentencing millions of people to hydrological poverty, a local form of poverty that is difficult to escape." "Water shortages will cause the world grain harvest to fall by some 160 million tons, "predicts the Worldwatch Institute. Governments in water-short countries must scramble to stabilize population and to raise water productivity, before their watershortages become food shortages. Brown says : "countries will not be able to afford to import needed hydrological poverty. Thirsty and hungry are unable to escape." "The only solution to this escalating problem is to stabilize population and to raise water productivity, "says Brown. In order to accomplish this, the price of water must be made to reflect its cost. Worldwide the cost of water is heavily subsidized, fostering inefficiency. "Once the price of water is raised, people will be forced to shift to more water-efficient technologies, more waterefficient crops, and more water efficient forms of animal protein, "says the Worldwatch Institute.