托福阅读：TPO3(Depletion of the Ogallala Aquifer)原文及答案

　　8. According to paragraph 4, all of following are consequences of the heavy use of the Ogallala aquifer for irrigation EXCEPT:

　　○The recharge rate of the aquifer is decreasing.

　　○Water tables in the region are becoming increasingly lower.

　　○Wells now have to be dug to much greater depths than before.

　　○Increasingly powerful pumps are needed to draw water from the aquifer.

　　9. According to paragraph 4, compared with all other states that use Ogallala water for irrigation, Texas

　　○has the greatest amount of farmland being irrigated with Ogallala water

　　○contains the largest amount of Ogallala water underneath the soil

　　○is expected to face the worst water supply crisis as the Ogallala runs dry

　　○uses the least amount of Ogallala water for its irrigation needs

　　Paragraph 5: The reaction of farmers to the inevitable depletion of the Ogallala varies. Many have been attempting to conserve water by irrigating less frequently or by switching to crops that require less water. Others, however, have adopted the philosophy that it is best to use the water while it is still economically profitable to do so and to concentrate on high-value crops such as cotton. The incentive of the farmers who wish to conserve water is reduced by their knowledge that many of their neighbors are profiting by using great amounts of water, and in the process are drawing down the entire region’s water supplies.

　　10. The word “inevitable” in the passage is closest in meaning to

　　○unfortunate

　　○predictable

　　○unavoidable

　　○final

　　11. Paragraph 5 mentions which of the following as a source of difficulty for some farmers who try to conserve water?

　　○Crops that do not need much water are difficult to grow in the High Plains.

　　○Farmers who grow crops that need a lot of water make higher profits.

　　○Irrigating less frequently often leads to crop failure.

　　○Few farmers are convinced that the aquifer will eventually run dry.

　　Paragraph 6: In the face of the upcoming water supply crisis, a number of grandiose schemes have been developed to transport vast quantities of water by canal or pipeline from the Mississippi, the Missouri, or the Arkansas rivers. Unfortunately, the cost of water obtained through any of these schemes would increase pumping

　　costs at least tenfold, making the cost of irrigated agricultural products from the region uncompetitive on the national and international markets. Somewhat more promising have been recent experiments for releasing capillary water (water in the soil) above the water table by injecting compressed air into the ground. Even if this process proves successful, however, it would almost triple water costs. Genetic engineering also may provide a partial solution, as new strains of drought-resistant crops continue to be developed. Whatever the final answer to the water crisis may be, it is evident that within the High Plains, irrigation water will never again be the abundant, inexpensive resource it was during the agricultural boom years of the mid-twentieth century.

　　12.According to paragraph 6, what is the main disadvantage of the proposed plans to transport river water to the High Plains?

　　○The rivers cannot supply sufficient water for the farmer’s needs.

　　○Increased irrigation costs would make the products too expensive.

　　○The costs of using capillary water for irrigation will increase.

　　○Farmers will be forced to switch to genetically engineered crops.

　　Paragraph 5: The reaction of farmers to the inevitable depletion of the Ogallala varies. Many have been attempting to conserve water by irrigating less frequently or by switching to crops that require less water. █Others, however, have adopted the philosophy that it is best to use the water while it is still economically profitable to do so and to concentrate on high-value crops such as cotton. █The incentive of the farmers who wish to conserve water is reduced by their knowledge that many of their neighbors are profiting by using great amounts of water, and in the process are drawing down the entire region’s water supplies. █

　　Paragraph 6: In the face of the upcoming water supply crisis, a number of grandiose schemes have been developed to transport vast quantities of water by canal or pipeline from the Mississippi, the Missouri, or the Arkansas rivers. █Unfortunately, the cost of water obtained through any of these schemes would increase pumping costs at least tenfold, making the cost of irrigated agricultural products from the region uncompetitive on the national and international markets. Somewhat more promising have been recent experiments for releasing capillary water (water in the soil) above the water table by injecting compressed air into the ground. Even if this process proves successful, however, it would almost triple water costs. Genetic engineering also may provide a partial solution, as new strains of drought-resistant crops continue to be developed. Whatever the final answer to the water crisis may be, it is evident that within the High Plains, irrigation water will never again be the abundant, inexpensive resource it was during the agricultural boom years of the mid-twentieth century.

　　13.Look at the four squares [█] that indicate where the following sentence could be added to the passage.

　　But even if uncooperative farmers were to join in the conservation efforts, this would only delay the depletion of the aquifer.

　　Where would the sentence best fit? Click on a square to add the sentence to the passage.

　　14.Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.

　　The Ogallala aquifer is a large underground source of water in the High Plains region of the United States.

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　　Answer choices

　　○The use of the Ogallala for irrigation has allowed the High Plains to become one of the most productive agricultural regions in the United States.

　　○Given the aquifer’s low recharge rate, its use for irrigation is causing water tables to drop and will eventually lead to its depletion.

　　○Releasing capillary water and introducing drought-resistant crops are less-promising solutions to the water supply crisis than bringing in river water

　　○The periodic deepening of wells and the use of more-powerful pumps would help increase the natural recharge rate of the Ogallala.

　　○In Texas, a great deal of attention is being paid to genetic engineering because it is there that the most critical situation exists.

　　○Several solutions to the upcoming water supply crisis have been proposed, but none of them promises to keep the costs of irrigation low.