文章大意:这是一篇说明文。养活不断增长的人口的需要给世界水资源供应带来了很大的压力。由于世界上97%的水太咸,不能饮用或用于农业,世界范围内的水供应需要仔细管理,特别是在农业方面。
Directions: After reading the passages below, fill in the blanks to make the passages coherent and grammatically correct. For the blanks with a given word, fill in each blank with the proper form of the given word; for the other blanks, use one word that best fits each blank.
The need to feed a growing population is putting much pressure on the world’s supply of water. With 97% of the world’s water too salty to be drunk or used in agriculture, the worldwide supply of water needs careful management, especially in agriculture. 11 the idea of a water shortage seems strange to someone fortunate enough to live in a high rainfall country, many of the world’s agricultural industries 12 (experience) constant water shortages.
Although dams can be built to store water for agricultural use in dry areas and dry seasons, the costs of water redistribution are very high. Not only is there the cost of the engineering itself, but there is also an environmental cost to be considered. One typical example is 13 where valleys are flooded to create dams, houses are lost and wildlife homes destroyed. Besides, water may flow easily through pipes to fields, but it cannot be transported from one side of the world to 14 . Each country 15 therefore rely on the management of its own water to supply its farming requirements.
This is particularly 16 (trouble) for countries with agricultural industries in areas dependent on irrigation. In Texas, farmers’ overuse of irrigation water 17 (result) in a 25% reduction of the water stores. In the Central Valley area of southwestern USA, a huge water engineering project provides water 18 farming in dry valleys, but much of the water use is being poorly managed.
Saudi Arabia’s attempts 19 (grow) wheat in desert areas have seen the pumping of huge quantities of irrigation water from underground reserves. Because there is no rainfall in these areas, such reserves can only decrease, and it is believed that fifty years of pumping 20 (see) them run dry.