1、雅思（阅读）历年真题试卷汇编 18 及答案解析(总分：80.00，做题时间：90 分钟)You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.OttersA Otters are semiaquatic(or in the case of the sea otter, aquatic)mammals. They are members of the Mustelid family which includes badgers, polecats, marte
2、ns, weasels, stoats and minks, and have inhabited the earth for the last 30 million years and over the years have undergone subtle changes to the carnivore bodies to exploit the rich aquatic environment. Otters have long thin body and short legsideal for pushing dense undergrowth or hunting in tunne
3、ls. An adult male may be up to 4 feet long and 30 pounds. Females are smaller, around 16 pounds typically. The Eurasian otters nose is about the smallest among the otter species and has a characteristic shape described as a shallow “W“. An otters tail(or rudder, or stern)is stout at the base and tap
4、ers towards the tip where it flattens. This forms part of the propulsion unit when swimming fast under water. Otter fur consists of two types of hair: stout guard hairs which form a waterproof outer covering, and under-fur which is dense and fine, equivalent to an otters thermal underwear. The fur m
5、ust be kept in good condition by grooming. Sea water reduces the waterproofing and insulating qualities of otter fur when salt water gets in the fur. This is why freshwater pools are important to otters living on the coast. After swimming, they wash the salts off in the pools and then squirm on the
6、ground to rub dry against vegetation.B Scent is used for hunting on land, for communication and for detecting danger. Otterine sense of smell is likely to be similar in sensitivity to dogs. Otters have small eyes and are probably shortsighted on land. But they do have the ability to modify the shape
7、 of the lens in the eye to make it more spherical, and hence overcome the refraction of water. In clear water and good light, otters can hunt fish by sight. The otters eyes and nostrils are placed high on its head so that it can see and breathe even when the rest of the body is submerged. The long w
8、hiskers growing around the muzzle are used to detect the presence of fish. They detect regular vibrations caused by the beat of the fishs tail as it swims away. This allows otters to hunt even in very murky water. Underwater, the otter holds its legs against the body, except for steering, and the hi
9、nd end of the body is flexed in a series of vertical undulations. River otters have webbing which extends for much of the length of each digit, though not to the very end. Giant otters and sea otters have even more prominent webs, while the Asian short-clawed otter has no webbingthey hunt for shrimp
10、s in ditches and paddy fields so they dont need the swimming speed. Otter ears are protected by valves which close them against water pressure.C A number of constraints and preferences limit suitable habitats for otters. Water is a must and the rivers must be large enough to support a healthy popula
11、tion of fish. Being such shy and wary creatures, they will prefer territories where mans activities do not impinge greatly. Of course, there must also be no other otter already in residencethis has only become significant again recently as populations start to recover. A typical range for a male riv
12、er otter might be 25km of river, a females range less than half this. However, the productivity of the river affects this hugely and one study found male ranges between 12 and 80km. Coastal otters have a much more abundant food supply and ranges for males and females may be just a few kilometers of
13、coastline. Because male ranges are usually larger, a male otter may find his range overlaps with two or three females. Otters will eat anything that they can get hold ofthere are records of sparrows and snakes and slugs being gobbled. Apart from fish the most common prey are crayfish, crabs and wate
14、r birds. Small mammals are occasionally taken, most commonly rabbits but sometimes even moles.D Eurasian otters will breed any time where food is readily available. In places where condition is more severe, Sweden for example where the lakes are frozen for much of winter, cubs are born in Spring. Th
15、is ensures that they are well grown before severe weather returns. In the Shetlands, cubs are born in summer when fish is more abundant. Though otters can breed every year, some do not. Again, this depends on food availability. Other factors such as food range and quality of the female may have an e
16、ffect. Gestation for Eurasian otter is 63 days, with the exception of North American river otter whose embryos may undergo delayed implantation.E Otters normally give birth in more secure dens to avoid disturbances. Nests are lined with bedding(reeds, waterside plants, grass)to keep the cubs warm wh
17、ile mummy is away feeding. Litter Size varies between 1 and 5(2 or 3 being the most common). For some unknown reason, coastal otters tend to produce smaller litters. At five weeks they open their eyesa tiny cub of 700g. At seven weeks theyre weaned onto solid food. At ten weeks they leave the nest,
18、blinking into daylight for the first time. After three months they finally meet the water and learn to swim. After eight months they are hunting, though the mother still provides a lot of food herself. Finally, after nine months she can chase them all away with a clear conscience, and relaxuntil the
19、 next fella shows up.F The plight of the British otter was recognised in the early 60s, but it wasnt until the late 70s that the chief cause was discovered. Pesticides, such as dieldrin and aldrin, were first used in 1955 in agriculture and other industriesthese chemicals are very persistent and had
20、 already been recognised as the cause of huge declines in the population of peregrine falcons, sparrowhawks and other predators. The pesticides entered the river systems and the food chainmicro-organisms, fish and finally otters, with every step increasing the concentration of the chemicals. From 19
21、62 the chemicals were phased out, but while some species recovered quickly, otter numbers did notand continued to fall into the 80s. This was probably due mainly to habitat destruction and road deaths. Acting on populations fragmented by the sudden decimation in the 50s and 60s, the loss of just a h
22、andful of otters in one area can make an entire population unviable and spell the end.G Otter numbers are recovering all around Britainpopulations are growing again in the few areas where they had remained and have expanded from those areas into the rest of the country. This is almost entirely due t
23、o law and conservation efforts, slowing down and reversing the destruction of suitable otter habitat and reintroductions from captive breeding programs. Releasing captive-bred otters is seen by many as a last resort. The argument runs that where there is no suitable habitat for them they will not su
24、rvive after release and where there is suitable habitat, natural populations should be able to expand into the area. However, reintroducing animals into a fragmented and fragile population may add just enough impetus for it to stabilise and expand, rather than die out. This is what the Otter Trust a
25、ccomplished in Norfolk, where the otter population may have been as low as twenty animals at the beginning of the 1980s. The Otter Trust has now finished its captive breeding program entirely. Great news because it means it is no longer needed.Questions 1-9Reading Passage 1 has seven paragraphs, A-G
26、. Which paragraph contains the following information? Write the correct letter, A-G, in boxes 1-9 on your answer sheet. NB You may use any letter more than once.（分数：18.00）(1).A description of how otters regulate vision underwater（分数：2.00）填空项 1:_(2).The fit-for-purpose characteristics of otters body
27、shape（分数：2.00）填空项 1:_(3).A reference to an underdeveloped sense（分数：2.00）填空项 1:_(4).An explanation of why agriculture failed in otter conservation efforts（分数：2.00）填空项 1:_(5).A description of some of the otters social characteristics（分数：2.00）填空项 1:_(6).A description of how baby otters grow（分数：2.00）填空项
28、 1:_(7).The conflicted opinions on how to preserve（分数：2.00）填空项 1:_(8).A reference to a legislative act（分数：2.00）填空项 1:_(9).An explanation of how otters compensate for heat loss（分数：2.00）填空项 1:_Answer the questions below.Choose NO MORE THAN TWO WORDS from the passage for each answer.Write your answers
29、in boxes 10-13 on your answer sheet.（分数：8.00）(1).What affects the outer fur of otters?（分数：2.00）填空项 1:_(2).What skill is not necessary for Asian short-clawed otters?（分数：2.00）填空项 1:_(3).Which type of otters has the shortest range?（分数：2.00）填空项 1:_(4).Which type of animals do otters hunt occasionally?（分
30、数：2.00）填空项 1:_Wealth in A Cold ClimateLatitude is crucial to a nations economic strength.A Dr William Masters was reading a book about mosquitoes when inspiration struck. “There was this anecdote about the great yellow-fever epidemic that hit Philadelphia in 1793,“ Masters recalls. This epidemic dec
31、imated the city until the first frost came.“ The inclement weather froze out the insects, allowing Philadelphia to recover.B If weather could be the key to a citys fortunes, Masters thought, then why not to the historical fortunes of nations? And could frost lie at the heart of one of the most endur
32、ing economic mysteries of allwhy are almost all the wealthy, industrialised nations to be found at latitudes above 40 degrees? After two years of research, he thinks that he has found a piece of the puzzle. Masters, an agricultural economist from Purdue University in Indiana, and Margaret McMillan a
33、t Tufts University, Boston, show that annual frosts are among the factors that distinguish rich nations from poor ones. Their study is published this month in the Journal of Economic Growth. The pair speculate that cold snaps have two main benefitsthey freeze pests that would otherwise destroy crops
34、, and also freeze organisms, such as mosquitoes, that carry disease. The result is agricultural abundance and a big workforce.C The academics took two sets of information. The first was average income for countries, the second climate data from the University of East Anglia. They found a curious tal
35、ly between the sets. Countries having five or more frosty days a month are uniformly rich, those with fewer than five are impoverished. The authors speculate that the five-day figure is important; it could be the minimum time needed to kill pests in the soil. Masters says: Tor example, Finland is a
36、small country that is growing quickly, but Bolivia is a small country that isnt growing at all. Perhaps climate has something to do with that.“ In fact, limited frosts bring huge benefits to farmers. The chills kill insects or render them inactive; cold weather slows the break-up of plant and animal
37、 material in the soil, allowing it to become richer; and frosts ensure a build-up of moisture in the ground for spring, reducing dependence on seasonal rains. There are exceptions to the “cold equals rich“ argument. There are well-heeled tropical places such as Hong Kong and Singapore, a result of t
38、heir superior trading positions. Likewise, not all European countries are moneyedin the former communist colonies, economic potential was crushed by politics.D Masters stresses that climate will never be the overriding factorthe wealth of nations is too complicated to be attributable to just one fac
39、tor. Climate, he feels, somehow combines with other factorssuch as the presence of institutions, including governments, and access to trading routesto determine whether a country will do well. Traditionally, Masters says, economists thought that institutions had the biggest effect on the economy, be
40、cause they brought order to a country in the form of, for example, laws and property rights. With order, so the thinking went, came affluence. “But there are some problems that even countries with institutions have not been able to get around,“ he says. “My feeling is that, as countries get richer,
41、they get better institutions. And the accumulation of wealth and improvement in governing institutions are both helped by a favourable environment, including climate.“E This does not mean, he insists, that tropical countries are beyond economic help and destined to remain penniless. Instead, richer
42、countries should change the way in which foreign aid is given. Instead of aid being geared towards improving governance, it should be spent on technology to improve agriculture and to combat disease. Masters cites one example: “There are regions in India that have been provided with irrigationagricu
43、ltural productivity has gone up and there has been an improvement in health.“ Supplying vaccines against tropical diseases and developing crop varieties that can grow in the tropics would break the poverty cycle.F Other minds have applied themselves to the split between poor and rich nations, citing
44、 anthropological, climatic and zoological reasons for why temperate nations are the most affluent. In 350BC, Aristotle observed that “those who live in a cold climate.are full of spirit“. Jared Diamond, from the University of California at Los Angeles, pointed out in his book Guns, Germs and Steel t
45、hat Eurasia is broadly aligned east-west, while Africa and the Americas are aligned north-south. So, in Europe, crops can spread quickly across latitudes because climates are similar. One of the first domesticated crops, einkorn wheat, spread quickly from the Middle East into Europe; it took twice a
46、s long for corn to spread from Mexico to what is now the eastern United States. This easy movement along similar latitudes in Eurasia would also have meant a faster dissemination of other technologies such as the wheel and writing, Diamond speculates. The region also boasted domesticated livestock,
47、which could provide meat, wool and motive power in the fields. Blessed with such natural advantages, Eurasia was bound to take off economically.G John Gallup and Jeffrey Sachs, two US economists, have also pointed out striking correlations between the geographical location of countries and their wea
48、lth. They note that tropical countries between 23.45 degrees north and south of the equator are nearly all poor. In an article for the Harvard International Review, they concluded that “development surely seems to favour the temperate-zone economies, especially those in the northern hemisphere, and
49、those that have managed to avoid both socialism and the ravages of war“. But Masters cautions against geographical determinism, the idea that tropical countries are beyond hope: “Human health and agriculture can be made better through scientific and technological research,“ he says, “so we shouldnt be writing off these countries. Take Singapore
