kl800.com省心范文网

tpo3阅读文本答案解析+翻译



托福TPO3阅读文本答案解析+翻译:Depletion of the Ogallala Aquifer

托福tpo3阅读原文

The vast grasslandsof the High Plains in the central United States were settled by farmers andranchers in the 1880s. This region has a semiarid climate, and for 50 yearsafter its settlement, it supported a low-intensity agricultural economy ofcattle ranching and wheat farming. In the early twentieth century, however, itwas discovered that much of the High Plains was underlain by a huge aquifer (arock layer containing large quantities of groundwater). This aquifer was namedthe Ogallala aquifer after the Ogallala Sioux Indians, who once inhabited theregion.

The Ogallalaaquifer is a sandstone formation that underlies some 583,000 square kilometersof land extending from northwestern Texas to southern South Dakota. Water fromrains and melting snows has been accumulating in the Ogallala for the past30,000 years.Estimates indicate that the aquifer contains enough water tofill Lake Huron, but unfortunately, under the semiarid climatic conditions thatpresently exist in the region, rates of addition to the aquifer are minimal,amounting to about half a centimeter a year.

The first wellswere drilled into the Ogallala during the drought years of the early 1930s. Theensuingrapid expansion of irrigation agriculture, especially from the1950s onward, transformed the economy of the region. More than 100,000 wellsnow tap the Ogallala. Modern irrigation devices, each capable of spraying 4.5million liters of water a day, have produced a landscape dominated by geometricpatterns of circular green islands of crops. Ogallala water has enabled theHigh Plains region to supply significant amounts of the cotton, sorghum, wheat,and corn grown in the United States. In addition, 40 percent of Americangrain-fed beef cattle are fattened here.

This unprecedented development of a finite groundwater resource with an almost negligible naturalrecharge rate—that is,virtually no natural water source to replenish the water supply—hascaused water tables in the region to fall drastically. In the 1930s, wellsencountered plentiful water at a depth of about 15 meters; currently, they mustbe dug to depths of 45 to 60 meters or more. In places, the water table isdeclining at a rate of a meter a year, necessitating the periodic deepening ofwells and the use of ever-more-powerful pumps. It is estimated that at currentwithdrawal rates, much of the aquifer will run dry within 40 years. Thesituation is most critical in Texas, where the climate is driest, the greatestamount of water is being pumped, and the aquifer contains the least water. Itis projected that the remaining Ogallala water will, by the year 2030, supportonly 35 to 40 percent of the irrigated acreage in Texas that is supported in1980.

The reaction offarmers to the inevitabledepletion of the Ogallala varies. Many havebeen attempting to conserve water by irrigating less frequently or by switchingto crops that require less water. Others, however, have adopted the philosophythat it is best to use the water while it is still economically profitable todo so and to concentrate on high-value crops such as cotton. The incentive ofthe farmers who wish to conserve water is reduced by their knowledge that manyof their neighbors are profiting by using great amounts of water, and in theprocess are drawing down the entire region’s water supplies.

In the face of theupcoming water supply crisis, a number of grandiose schemes have been developedto transport vast quantities of water by canal or pipeline from theMississippi, the Missouri, or the Arkansas rivers. Unfortunately, the cost ofwater obtained through any of these schemes would increase pumping costs atleast tenfold, making the cost of irrigated agricultural products from theregion uncompetitive on the national and international markets. Somewhat morepromising have been recent experiments for releasing capillary water (water inthe soil) above the water table by injecting compressed air into the ground.Even if this process proves successful, however, it would almost triple watercosts. Genetic engineering also may provide a partial solution, as new strainsof drought-resistant crops continue to be developed. Whatever the final answerto the water crisis may be, it is evident that within the High Plains,irrigation water will never again be the abundant, inexpensive resource it wasduring the agricultural boom years of the mid-twentieth century.

托福tpo3阅读试题

1. According toparagraph 1, which of the following statements about the High Plains is true?

A.Until farmers andranchers settled there in the 1880s, the High Plains had never been inhabited.

B.The climate ofthe High Plains is characterized by higher-than-average temperatures.

C.The large aquiferthat lies underneath the High Plains was discovered by the Ogallala SiouxIndians.

D.Before the early1900s there was only a small amount of farming and ranching in the High Plains.

2. According toparagraph 2, all of the following statements about the Ogallala aquifer aretrue EXCEPT:

A.The aquiferstretches from South Dakota to Texas.

B.The aquifer’s water comes from underground springs.

C.Water has beengathering in the aquifer for 30,000 years.

D.The aquifer’s water is stored in a layer ofsandstone.

3. Which of thesentences below best expresses the essential information in thehighlightedsentencein the passage (paragragh 2)? Incorrect choices change the meaningin important ways or leave out essential information.

A.Despite thecurrent impressive size of the Ogallala aquifer, the region’s climate keeps the rates of wateraddition very small.

B.Although theaquifer has been adding water at the rate of only half a centimeter a year, itwill eventually accumulate enough water of fill Lake Huron.

C.Because of theregion’s present climaticconditions, water is being added each year to the aquifer.

D.Even when theregion experiences unfortunate climatic conditions, the rates of addition ofwater continue to increase.

4. The word “ensuing”in the passage (paragraph 3) is closest inmeaning to

A.continuing

B.surprising

C.initial

D.subsequent

5. In paragraph 3,why does the author provide the information that 40 percent of American cattleare fattened in the High Plains?

A.To suggest thatcrop cultivation is not the most important part of the economy of the HighPlains

B.To indicate thatnot all economic activity in the High Plains is dependent on irrigation

C.To provideanother example of how water from the Ogallala has transformed the economy ofthe High Plains

D.To contrastcattle-fattening practices in the High Plains with those used in other regionof the United States

6. The word “unprecedented”in the passage (paragraph 4) is closest in meaning to

A.difficult tocontrol

B.without anyrestriction

C.unlike anythingin the past

D.rapidly expanding

7. The word “virtually”in the passage (paragraph 4) is closest in meaning to

A.clearly

B.perhaps

C.frequently

D.almost

8. According toparagraph 4, all of following are consequences of the heavy use of the Ogallalaaquifer for irrigation EXCEPT:

A.The recharge rateof the aquifer is decreasing.

B.Water tables inthe region are becoming increasingly lower.

C.Wells now have tobe dug to much greater depths than before.

D.Increasinglypowerful pumps are needed to draw water from the aquifer.

9. According toparagraph 4, compared with all other states that use Ogallala waterforirrigation, Texas

A.has the greatestamount of farmland being irrigated with Ogallala water

B.contains thelargest amount of Ogallala water underneath the soil

C.is expected toface the worst water supply crisis as the Ogallala runs dry

D.uses the leastamount of Ogallala water for its irrigation needs

10. The word “inevitable”in the passage (paragraph 5) is closest in meaning to

A.unfortunate

B.predictable

C.unavoidable

D.final

11. Paragraph 5 mentionswhich of the following as a source of difficulty for some farmers who try toconserve water?

A.Crops that do notneed much water are difficult to grow in the High Plains.

B.Farmers who growcrops that need a lot of water make higher profits.

C.Irrigating lessfrequently often leads to crop failure.

D.Few farmers areconvinced that the aquifer will eventually run dry.

12. According toparagraph 6, what is the main disadvantage of the proposed plans to transportriver water to the High Plains?

A.The rivers cannotsupply sufficient water for the farmer’s needs.

B.Increasedirrigation costs would make the products too expensive.

C.The costs ofusing capillary water for irrigation will increase.

D.Farmers will beforced to switch to genetically engineered crops.

13. Look at thefour squares that indicate wherethe following sentence could be added to the passage.But even ifuncooperative farmers were to join in the conservation efforts, this would onlydelay the depletion of the aquifer.

The reaction offarmers to the inevitable depletion of the Ogallala varies. Many have beenattempting to conserve water by irrigating less frequently or by switching tocrops that require less water. Others, however, have adopted the philosophy that it is best to usethe water while it is still economically profitable to do so and to concentrateon high-value crops such as cotton.The incentive ofthe farmers who wish to conserve water is reduced by their knowledge that manyof their neighbors are profiting by using great amounts of water, and in theprocess are drawing down the entire region’s watersupplies.

In the face of theupcoming water supply crisis, a number of grandiose schemes have been developedto 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 theseschemes would increase pumping costs at least tenfold, making the cost ofirrigated agricultural products from the region uncompetitive on the nationaland international markets. Somewhat more promising have been recent experimentsfor releasing capillary water (water in the soil) above the water table byinjecting compressed air into the ground. Even if this process provessuccessful, however, it would almost triple water costs. Genetic engineeringalso 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 evident that within the High Plains, irrigation water will never again bethe abundant, inexpensive resource it was during the agricultural boom years ofthe mid-twentieth century.

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

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

The Ogallalaaquiferis a large underground source of water in the High Plains region of theUnitedStates.

A.The use of theOgallala for irrigation has allowed the High Plains to become one of the mostproductive agricultural regions in the United States.

B.Given the aquifer’s low recharge rate, its use forirrigation is causing water tables to drop and will eventually lead to itsdepletion.

C.Releasingcapillary water and introducing drought-resistant crops are less-promisingsolutions to the water supply crisis than bringing in river water

D.The periodicdeepening of wells and the use of more-powerful pumps would help increase thenatural recharge rate of the Ogallala.

E.In Texas, a greatdeal of attention is being paid to genetic engineering because it is there thatthe most critical situation exists.

F.Several solutionsto the upcoming water supply crisis have been proposed, but none of thempromises to keep the costs of irrigation low.

托福tpo3阅读答案

1.排除法,以1880s做关键词定位至第一句,说1880s农牧民定居在High Plains,没说1880前没有人,A错;以climate做关键词定位至第二句,原文说semiarid,没说温度,B错;以人名做关键词定位至最后一句,说这个人是inhabit在这儿的,没说是他发现的,C错;D中small amount of farming and ranching和原文中的low-density是同义替换,选

2.排除法,以两个地名做关键词定位至第一句,A和D都对,不选;以30000 years做关键词定位至第二句,C对,不选;同时可以看到地下水是来自rain and melting snow,不是泉水,所以B错,选

3.原文的结构是估计水很多,足以填满休伦湖,但补充的少;A答案完整地反映了这两个方面,正确;B强调的点搞反,原句强调的是补充的少,B强调的是现在的量大;C的因果关系是原文没有的;D说补充的持续增长,原文没说

4.ensue跟随,接下来,所以subsequent是答案。原文说第一批水井是1930s挖掘的,ensuing所在的那句话又说1950s什么样的农业的快速扩张,这两个时间说明动作是有先后的,而且first一般必然有下文的,所以应该是接着的。注意continuing是个很大的迷惑项,继续是指一个动作的延续,而接下来是两件事情接着发生,B令人吃惊和C最初的,起始的都不对

5.修辞目的题,40%明显是一个例子,往前看,说这个地方的水养活了high plains地区的很多农作物,in addition说明进一步,也就是除了农业还有牧业,所以是C,provide another example,没有说农业和牧业谁重要,A错;牧业确实不依赖灌溉,但也依赖这个地方的水,所以B无关;没有对比,D错

6.unprecedented史无前例的,un表示没有,pre前,想到precede,在……之前。A难以控制和B毫无限制都有轻微贬义,而原词只是在叙述一个事实,属中性。D快速扩张也不沾边,而且A/B/D三个选项在意思上有共同点,唯独C不同,只要知道pre是前就一定能选出答案

7.virtually几乎。注意virtual有虚拟和真实两个截然相反的意思,破折号之前说negligible recharge rate,补给可以忽略,就是很少,但还是有的,后面解释说什么没有水补充,如果选除了almost之外的三项,都说明可能没水,与原文意思不符

8.排除法,分别以recharge rate,water tables,wells,powerfulpumps做关键词定位至本段前三句,B/C/D三项在原文中都有说,所以A错,选。而且跳出这道题看,随着地下水位的下降,井必须打得更深,水泵必须功率更大,这是一系列的因果关系,只有A不是这个因果序列中的

9.以Texas为关键词定位至倒数第二句,说德州气候最干燥,地下水最少,面临的问题最严峻,C是原文的同义改写

10.inevitable不可避免的,必然的。上段整个都在说地下水位在剧烈下降,depletion指的是水用光,承上启下应该是地下水一定会用光,作者只是在陈述事实,没有好坏之说,所以unfortunate不对,不要主观猜想水没了对当地人一定不好;predictable可预见的夜不对,因为原文没给出任何预见性的信息;就单词本身看,in前缀表示否定,所以必须答案也有类似的部分,unavoidable无疑是最好的选项

11.以some farmers who try to conserve water为关键词定位至最后一句,说那些不省水的农民因为没有节约水获得利润,众多选项中只有B提到了利润问题,是正确答案

12.以transport water做关键词定位至本段第一句,第二句开始的unfortunately清楚的表明了这句话会说一个运水产生的问题,就是成本太贵,使产品价格失去竞争力,B和C提到成本,而只有B提到了产品价格升高,正确

13.两个决定点,第一个是uncooperative farmers,那些不合作的农民,根据这个点,A和C是可能的答案,第二个点就是evenif的让步,既然待插入句说即使那些人愿意合作,正确插入点之前就必须的说那些人不合作,所以C是正确答案,而且A前后的many一句和other一句衔接很紧密,不插入句子

14.The use选项对应原文第三段,改变了当地经济,正确

Given选项对应原文第四、第五段首句,正确

Releasing选项与原文意思相反,但即使正确也是细节,不选

The periodic选项原文没说,不选,即使说了也是细节,不选

In Texas选项太细节,不选

Several选项对应原文第六段第一句,正确

托福tpo3阅读译文

19世纪80年代,在美国中部北美大平原的广阔草原上定居着农场主们和牧场主们。这里有着半干旱的气候,在人们定居50年后,它支撑了一个以畜牧业和小麦种植为主的低密度农业经济。然而,在20世纪初,人们发现北美大平原的大部地下是巨大的蓄水层(含有大量地下水的岩层)。这个蓄水层因曾经在这里定居过的奥加拉拉苏族印第安人而得名,被称作奥加拉拉蓄水层。

奥加拉拉蓄水层属于砂岩结构,在从德克萨斯州西北到南达科塔州南部的地下绵延了58.3万平方公里。雨水和融雪自3万年前便开始在奥加拉拉蓄积。据估计,奥加拉拉蓄水层的含水量足以填满休伦湖,但不幸的是,在目前该地区半干旱的气候条件下,奥加拉拉蓄水层的蓄水能力极低,每年仅半厘米左右。

20世纪30年代初,奥加拉拉正处于干旱时期,人们打出了第一口井。灌溉农业的迅速扩张,特别是20世纪50年代之后,改变了这一地区的经济。目前人们已经在奥加拉拉地区共开凿了10万多口井。日喷水量达到450万升的现代灌溉设备,形成了一个圆形绿岛作物为主的景观。奥加拉拉蓄水层支撑了北美大平原地区棉花、高粱、小麦、玉米的灌溉需求。此外,美国40%谷饲养的肉牛在这里被育肥。

考虑到几乎没有补充率(实质上没有自然水资源进行补充),这种有限地下水资源前所未有的发展已经引起了该地区地下水位的急剧下降。在20世纪30年代,井下15米就有丰富的水资源,而现在,必须挖掘到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达到了每年1米,迫使人们周期性的加深水井并使用更有力的水泵。按现今的下降速度来估计,大部分地下蓄水将在40年内耗尽。这种现象在气候最干旱的德克萨斯州尤为严重。大量的水被从地下抽起,蓄水层含水量最少。据估计,到2030年,德克萨斯州余下的奥加拉拉含水只能支持1980年灌溉面积的35%到40%。

农场主们对无法避免的奥加拉拉蓄水层枯竭的反应各不相同。很多人已经开始尝试通过降低灌溉频率或者改种需水较少的庄稼来节约水资源。而另外一些人却抱着趁水资源还能产生经济效益就应抓紧利用的想法,继续种植高价值的棉花等农作物。当那些想节水的农场主得知邻居们通过大量耗水的种植而盈利的时候,他们的热情降低了,从而导致了整个区域的供水量的减少。

在即将到来的水资源供应危机面前,人们提出了一些宏伟的供水计划,比如将密西西比河、密苏里河或者阿肯色河的水通过运河或管道运到需要用水的地方。不幸的是,通过以上任何一种方式获得水资源都会将抽水的成本提高10倍以上,进而导致这一地区的灌溉农产品成本在国内和国际市场上失去竞争力。最近一些有希望获得成功的试验试图通过向土壤中注入压力,释放水层上方土壤中的毛细管水。即使这样行之有效,抽水成本会变到原来的3倍。基因工程也会通过继续研发抗旱作物新品种,帮助解决部分难题。无论这次水资源危机的最终结果如何,显然,北美大平原地区灌溉水资源再也不会像20世纪中期农业繁荣时期的那样充足并且廉价了。

以上就是小马小编整理的tpo3阅读文本答案解析+翻译,希望考生们可以认真学习。如果想了解最新托福考试资讯,请关注小马过河托福频道,关于本文有任何疑问,都可以和小马过河专家联系。



赞助商链接