2002年英语专业四级考试阅读真题：text F

　　TEXT F

　　First read the following question.
　　82. The main topic of the passage is ___.
　　A. agricultural products
　　B. irrigation methods
　　C. natural resources
　　D. water shortages

　　Now, go through TEXT F quickly and answer question 82.
　　It is widely accepted that China is a country faced with severe water shortages. Insufficient water resources have slowed agricultural development. And to make matters worse, some of the traditional Chinese irrigation methods have wasted an astonishing amount of water.
　　In China today, the utilization efficiency of farming water is about 30-40 per cent. This figure stands in sharp contrast to developed countries’ utilization average of 70-80 per cent. The low utilization efficiency has resulted from the adoption of some traditional Chinese irrigation methods.
　　Only by using modern irrigation methods can we reduce water shortage in agriculture.
　　One of the advantages of modern irrigation methods is that they alone can save 20-30 per cent of the present volume of wasted irrigation water.