駿馬是跑出來的，強兵是打出來的。以下是小編為大家搜尋整理的2017年託福練習試題，希望對大家有所幫助!更多精彩內容請及時關注我們應屆畢業生考試網!
The vast grasslands of the High Plains in the central United States were settled by farmers andranchers in the 1880’s. This region has a semiarid climate, and for 50 years after its settlement,it supported a low-intensity agricultural economy of cattle ranching and wheat farming. In theearly twentieth century, however, it was discovered that much of the High Plains was underlainby a huge aquifer (a rock layer containing large quantities of groundwater). This aquifer wasnamed the Ogallala aquifer after the Ogallala Sioux Indians, who once inhabited the region.
The Ogallala aquifer is a sandstone formation that underlies some 583,000 square kilometersof land extending from northwestern Texas to southern South Dakota. Water from rains andmelting snows has been accumulating in the Ogallala for the past 30,000 years. Estimatesindicate that the aquifer contains enough water to fill Lake Huron, but unfortunately, under thesemiarid climatic conditions that presently exist in the region, rates of addition to the aquiferare minimal, amounting to about half a centimeter a year.
The first wells were drilled into the Ogallala during the drought years of the early 1930’s. Theensuing rapid expansion of irrigation agriculture, especially from the 1950’s onward,transformed the economy of the region. More than 100,000 wells now tap the Ogallala. Modernirrigation devices, each capable of spraying 4.5 million liters of water a day, have produced alandscape dominated by geometric patterns of circular green islands of crops. Ogallala waterhas enabled the High Plains region to supply significant amounts of the cotton, sorghum,wheat, and corn grown in the United States. In addition, 40 percent of American grain-fedbeef cattle are fattened here.
This unprecedented development of a finite groundwater resource with an almost negligiblenatural recharge rate—that is, virtually no natural water source to replenish the water supply—has caused water tables in the region to fall drastically. In the 1930’s, wells encounteredplentiful water at a depth of about 15 meters; currently, they must be dug to depths of 45 to60 meters or more. In places, the water table is declining at a rate of a meter a year,necessitating the periodic deepening of wells and the use of ever-more-powerful pumps. It isestimated that at current withdrawal rates, much of the aquifer will run dry within 40 situation is most critical in Texas, where the climate is driest, the greatest amount of wateris being pumped, and the aquifer contains the least water. It is projected that the remainingOgallala water will, by the year 2030, support only 35 to 40 percent of the irrigated acreage inTexas that is supported in 1980.
The reaction of farmers to the inevitable depletion of the Ogallala varies. Many have beenattempting to conserve water by irrigating less frequently or by switching to crops that requireless water. Other, however, have adopted the philosophy that it is best to use the water while itis still economically profitable to do so and to concentrate on high-value crops such ascotton. The incentive of the farmers who wish to conserve water is reduced by theirknowledge that many of their neighbors are profiting by using great amounts of water, and inthe process are drawing down the entire region’s water supplies.
In the face of the upcoming water supply crisis, a number of grandiose schemes have beendeveloped to transport vast quantities of water by canal or pipeline from the Mississippi, theMissouri, or the Arkansas rivers. Unfortunately, the cost of water obtained through any ofthese schemes would increase pumping costs at least tenfold, making the cost of irrigatedagricultural products from the region uncompetitive on the national and international what more promising have been recent experiments for releasing capillary water (waterin the soil) above the water table by injecting compressed air into the ground. Even if thisprocess proves successful, however, it would almost triple water costs. Genetic engineering alsomay provide a partial solution, as new strains of drought-resistant crops continue to bedeveloped. Whatever the final answer to the water crisis may be, it is evident that within theHigh Plains, irrigation water will never again be the abundant, inexpensive resource it wasduringthe agricultural boom years of the mid-twentieth century.
Paragraph 1：The vast grasslands of the High Plains in the central United States were settledby farmers and ranchers in the 1880’s. This region has a semiarid climate, and for 50 yearsafter its settlement, it supported a low-intensity agricultural economy of cattle ranching andwheat farming. In the early twentieth century, however, it was discovered that much of theHigh Plains was underlain by a huge aquifer (a rock layer containing large quantities ofgroundwater). This aquifer was named the Ogallala aquifer after the Ogallala Sioux Indians, whoonce inhabited the region.
rding to paragraph 1, which of the following statements about the High Plains is true?
○Until farmers and ranchers settled there in the 1880’s, the High Plains had never beeninhabited.
○The climate of the High Plains is characterized by higher-than-average temperatures.
○The large aquifer that lies underneath the High Plains was discovered by the Ogallala SiouxIndians.
○Before the early 1900’s there was only a small amount of farming and ranching in the HighPlains.
Paragraph 2：The Ogallala aquifer is a sandstone formation that underlies some 583,000square kilometers of land extending from northwestern Texas to southern South r from rains and melting snows has been accumulating in the Ogallala for the past 30,000years. Estimates indicate that the aquifer contains enough water to fill Lake Huron, butunfortunately, under the semiarid climatic conditions that presently exist in the region, rates ofaddition to the aquifer are minimal, amounting to about half a centimeter a year.
2. According to paragraph 2, all of the following statements about the Ogallala aquifer are trueEXCEPT:
○The aquifer stretches from South Dakota to Texas.
○The aquifer’s water comes from underground springs.
○Water has been gathering in the aquifer for 30,000 years.
○The aquifer’s water is stored in a layer of sandstone.
3. Which of the sentences below best expresses the essential information in the highlightedsentence in the passage? Incorrect choices change the meaning in important ways or leave outessential information.
○Despite the current impressive size of the Ogallala aquifer, the region’s climate keeps therates of water addition very small.
○Although the aquifer has been adding water at the rate of only half a centimeter a year, it willeventually accumulate enough water of fill Lake Huron.
○Because of the region’s present climatic conditions, water is being added each year to theaquifer.
○Even when the region experiences unfortunate climatic conditions, the rates of addition ofwater continue to increase.
Paragraph 3: The first wells were drilled into the Ogallala during the drought years of the early1930’s. The ensuing rapid expansion of irrigation agriculture, especially from the 1950’sonward, transformed the economy of the region. More than 100,000 wells now tap theOgallala. Modern irrigation devices, each capable of spraying 4.5 million liters of water a day,have produced a landscape dominated by geometric patterns of circular green islands ofcrops. Ogallala water has enabled the High Plains region to supply significant amounts of thecotton, sorghum, wheat, and corn grown in the United States. In addition, 40 percent ofAmerican grain-fed beef cattle are fattened here.
4. The word “ensuing” in the passage is closest in meaning to
○Continuing
○Surprising
○Initial
○Subsequent
5. In paragraph 3, why does the author provide the information that 40 percent of Americancattle are fattened in the High Plains?
○To suggest that crop cultivation is not the most important part of the economy of the HighPlains
○To indicate that not all economic activity in the High Plains is dependent on irrigation
○To provide another example of how water from the Ogallala has transformed the economy ofthe High Plains
○To contrast cattle-fattening practices in the High Plains with those used in other region ofthe United States
Paragraph 4：This unprecedented development of a finite groundwater resource with analmost negligible natural recharge rate—that is, virtually no natural water source to replenishthe water supply—has caused water tables in the region to fall drastically. In the 1930’s, wellsencountered plentiful water at a depth of about 15 meters; currently, they must be dug todepths of 45 to 60 meters or more. In places, the water table is declining at a rate of a metera year, necessitating the periodic deepening of wells and the use of ever-more-powerfulpumps. It is estimated that at current withdrawal rates, much of the aquifer will run drywithin 40 years. The situation is most critical in Texas, where the climate is driest, the greatestamount of water is being pumped, and the aquifer contains the least water. It is projected thatthe remaining Ogallala water will, by the year 2030, support only 35 to 40 percent of theirrigated acreage in Texas that is supported in 1980.
6. The word “unprecedented” in the passage is closest in meaning to
○Difficult to control
○Without any restriction
○Unlike anything in the past
○Rapidly expanding
7. The word “virtually” in the passage is closest in meaning to
○Clearly
○Perhaps
○Frequently
○Almost
8. According to paragraph 4, all of following are consequences of the heavy use of the Ogallalaaquifer 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 forirrigation, 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. Manyhave been attempting to conserve water by irrigating less frequently or by switching to cropsthat require less water. Other, however, have adopted the philosophy that it is best to use thewater while it is still economically profitable to do so and to concentrate on high-value cropssuch as cotton. The incentive of the farmers who wish to conserve water is reduced by theirknowledge that many of their neighbors are profiting by using great amounts of water, and inthe 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
graph 5 mentions which of the following as a source of difficulty for some farmers whotry 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 schemeshave been developed to transport vast quantities of water by canal or pipeline from theMississippi, the Missouri, or the Arkansas rivers. Unfortunately, the cost of water obtainedthrough any of these schemes would increase pumping costs at least tenfold, making the costof irrigated agricultural products from the region uncompetitive on the national and internationalmarkets. Somewhat more promising have been recent experiments for releasing capillarywater (water in the soil) above the water table by injecting compressed air into the if this process proves successful, however, it would almost triple water costs. Geneticengineering also may provide a partial solution, as new strains of drought-resistant cropscontinue to be developed. Whatever the final answer to the water crisis may be, it is evidentthat within the High Plains, irrigation water will never again be the abundant, inexpensiveresource it was during the agricultural boom years of the mid-twentieth century.
rding to paragraph 6, what is the main disadvantage of the proposed plans totransport 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—6：The reaction of farmers to the inevitable depletion of the Ogallala have been attempting to conserve water by irrigating less frequently or by switching tocrops that require less water.█ Other, however, have adopted the philosophy that it is best touse the water while it is still economically profitable to do so and to concentrate on high-valuecrops such as cotton.█ The incentive of the farmers who wish to conserve water is reducedby 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.█
In the face of the upcoming water supply crisis, a number of grandiose schemes have beendeveloped to transport vast quantities of water by canal or pipeline from the Mississippi, theMissouri, or the Arkansas rivers. █Unfortunately, the cost of water obtained through any ofthese schemes would increase pumping costs at least tenfold, making the cost of irrigatedagricultural products from the region uncompetitive on the national and international what more promising have been recent experiments for releasing capillary water (waterin the soil) above the water table by injecting compressed are into the ground. Even if thisprocess proves successful, however, it would almost triple water costs. Genetic engineering alsomay provide a partial solution, as new strains of drought-resistant crops continue to bedeveloped. Whatever the final answer to the water crisis may be, it is evident that within theHigh Plains, irrigation water will never again be the abundant, inexpensive resource it wasduring the agricultural boom years of the mid-twentieth century.
at the four squares [█] that indicate where the following sentence could be added tothe passage.
But even if uncooperative farmers were to join in the conservation efforts, this would onlydelay the depletion of the aquifer.
Where would the sentence best fit? Click on a square to add the sentence to the passage.
ctions: An introductory sentence for a brief summary of the passage is providedbelow. Complete the summary by selecting the THREE answer choices that express the mostimportant ideas in the passage. Some sentences do not belong in the summary because theyexpress ideas that are not presented in the passage or are minor ideas in the passage. Thisquestion is worth 2 points.
The Ogallala is a large underground source of water in the High Plains region of the UnitedStates.
●
●
●
Answer choices
○The use of the Ogallala for irrigation has allowed the High Plains to become one of the mostproductive agricultural regions in the United States.
○Given the aquifer’s low recharge rate, its use for irrigation is causing water tables to drop andwill eventually lead to its depletion.
○Releasing capillary water and introducing drought-resistant crops are less-promisingsolutions 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 thenatural recharge rate of the Ogallala.
○In Texas, a great deal of attention is being paid to genetic engineering because it is therethat the most critical situation exists.
○Several solutions to the upcoming water supply crisis have been proposed, but none of thempromises to keep the costs of irrigation low.
1. ○4
2. ○2
3. ○1
4. ○4
5. ○3
6. ○3
7. ○4
8. ○1
9. ○3
10. ○3
11. ○2
12. ○2
13. ○3
14. ○1 2 6
參考譯文
奧加拉拉蓄水層的枯竭
19世紀80年代，在美國中部北美大平原的廣闊草原上定居著農民和農場主們。這裡有著半乾旱的氣候，在人們定居50年後，它支撐了一個以畜牧業和小麥種植為主的低密度農業經濟。然而，在20世紀初，人們發現北美大平原的大部下面是巨大的蓄水層(含有大量地下水的岩層)。這個蓄水層因曾經在這裡定居過的奧加拉拉蘇族印第安人而得名，被稱作奧加拉拉蓄水層。
奧加拉拉蓄水層屬於砂岩結構，在從德克薩斯州西北到南達科塔州的地下綿延了583000平方公里。雨水和融雪自30000年前便開始在奧加拉拉蓄積。據估計，奧加拉拉蓄水層的含水量足以填滿休倫湖，但不幸的是，在目前該地區半乾旱的氣候條件下，奧加拉拉蓄水層的蓄水能力極低，每年僅半釐米左右。
20世紀30年代初，奧加拉拉正處於乾旱時期，人們打出了第一口井。灌溉農業的迅速擴張，特別是20世紀50年代之後，改變了這一地區的經濟。目前人們已經在奧加拉拉地區共開鑿了100000多口井。日噴水量達到4500000升的現代灌溉裝置，形成了一個圓形綠島作物為主的景觀。奧加拉拉蓄水層支撐了北美大平原地區美國棉花、高粱、小麥、玉米的灌溉需求。此外，美國百分之四十谷飼養的肉牛在這裡被育肥。
考慮到幾乎沒有補充率(實質上沒有自然水資源進行補充)，這種有限地下水資源前所未有的發展已經引起了該地區地下水位的急劇下降。在20世紀30年代，井下15米就有豐富的水資源，而現在，必須挖掘到45米到60米甚至更深的地方才行。有的地方地下水位的下降速度甚至達到了每年1米，迫使人們週期性的加深水井並使用更有力的的水泵。按現今的下降速度來估計，大部分地下蓄水將在40年內耗盡。這種現象在氣候最乾旱的德克薩斯州尤為嚴重。大量的水被從地下抽起，蓄水層含水量最少。據估計，到2030年，德克薩斯州餘下的奧加拉拉含水只能支援1980年灌溉面積的30%到40%。
農民們對無法避免的奧加拉拉蓄水層枯竭的反應各不相同。很多人已經開始嘗試通過降低灌溉頻率或者改種需水較少的莊稼來節約水資源。而另外一些人卻抱著趁水資源還能產生經濟效益就應抓緊利用的想法，繼續種植高價值的棉花等農作物。當那些想節水的'農民得知鄰居們通過大量耗水的種植而盈利的時候，他們的熱情降低了，從而導致了整個區域的供水量的減少。
在即將到來的水資源供應危機面前，人們提出了一些巨集偉的供水計劃，比如將密西西比河、密蘇里河或者阿肯色河的水通過運河或管道運到需要用水的地方。不幸的是，通過以上任何一種方式獲得水資源都會將抽水的成本提高十倍以上，進而導致這一地區的灌溉農產品成本在國內和國際市場上都毫無競爭力。最近一些有希望獲得成功的試驗試圖通過向土壤中注入壓力，釋放水層上方土壤中的毛細管水。即使這樣行之有效，抽水成本會變到原來的三倍。基因工程也會通過繼續研發抗旱作物新品種，幫助解決部分難題。無論這次水資源危機的最終結果如何，顯然，北美大平原地區灌溉水資源再也不會像20世紀中期農業繁榮時期的那樣充足並且廉價了。
