【答案解析】{{B}} Giant Yangtze Clean Up{{/B}} China's longest river，the Yangtze，witnessed a major reduction in pollution in 2002，experts have revealed. About 22 billion tons of industrial waste and daily sewage was discharged into the river in 2001, 1.4 billion tons less than the previous year, according to the latest communique from the Yangtze River Water Resources Committee. A contributory factor to the cut in pollution along china's longest river is that its major centers to process sewage and industrial waste. And these cities are constructing more sewage farms. However, owing to ballooning populations along the river and vigorous industrial and agricultural production, as well as speedy modernization, the Yangtze still faces severe water pollution. But experts were confident that. as the industrial waste processing capability increases step by step, the river's water pollution still can be alleviated.