2021年10月23日雅思考试机经回忆完整版(3)

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2023-06-07 16:04:31|已浏览：75次

2021年10月23日雅思考试机经回忆完整版(3) 关于这个问题下面小编就来为各个考生解答下。

2021.10.23

READING

Passage 1

Topic 淘金城市gold mine and rush

1-6为判断题

1. snow and wind are the most dificult problems in conserving the city True

2. Not Given

3. Not Given

4. False

5. False

6. True

7-10为填空题

7. Valley

8. Zinc

9. Copper

10. Sand

11-13暂缺

Bird Migration

Birds have many unique design features that enable them to perform such amazing feats of endurance. They are equipped with lightweight, hollow bones,intricately designed features providing both lift and trust for rapid flight, navigation systems superior to ant that man has developed, and an ingenious heat conserving design that, among other things, concentrates all blood circulation beneath layers of warm, waterproof plumage, leaving them fit to face life in the harshest of climates. Their respiratory systems have to perform efficiently during sustained flights at altitude.so they have a system of extracting oxygen from their lungs that far exceeds that of any other animal. During the later stages of accumulate considerable layers of fat, in order to provide sufficient energy for their long migratory flights.The fundamental reason that birds migrate is to find adequate food during the winter months when it is in short supply. This particularly applies to birds that breed in the temperate and Arctic regions of the Northern Hemisphere, where food is abundant during the short growing season. Many species can tolerate cold temperatures if food is plentiful, but when food is not available they must migrate. However, intriguing questions remain. necessary just to find food and good weather. Nobody knows, for instance, why British swallows, which could presumably survive equally well if they spent the winter in equatorial Africa, instead fly several thousands of miles further to their preferred winter home in South Africa' Cape Province. Another mystery involves the huge migrations performed by arctic tems and mudflat-feeding shorebirds that breed close to Polar Regions. In general, the further north a migrant species breeds, the further south it spends the winter. For arctic terns this necessitated an annual round trip of 25000 miles. Yet, en route to their final destination in far-flung southern latitudes, all these individuals overfly other areas of seemingly suitable habitat spanning two hemispheres. While we may not fully understand birds' reasons for going to particular places, we can marvel at their feats,

One of the greatest mysteries is how young birds know how to find the traditional wintering areas without parental guidance. Very few adults migrate with juveniles in tow, and youngsters may even have lttle or no inkling of their parents' appearance. A familiar example is that of the cuckoo, which lays its eggs in another species' nest and never encounters its young again. It is mind boggling to consider that, once raised by its host species, the young cuckoo makes it own way to ancestral wintering grounds in the tropics before returning single-handedly to northern Europe the next season to seek out a mate among its own kind. The obvious implication is that it inherits from its parents an inbuilt route map and direction-finding capability, as well as a mental image of what another cuckoo looks like. Yet nobody has the slightest idea as to how this is

possible.

Mounting evidence has confirmed that birds use the positions of the sun and stars to obtain compass directions. They seem also to be able to detect the earth's magnetic field, probably due to having minute crystals of magnetite in the region of their brains. However, true navigation also requires an awareness

of position and time, especially when lost. Experiments have shown that afer being taken thousands of miles over an unfamiliar landmass, birds are still capable of returning rapidly to nest sites. Such phenomenal powers are the product of computing a number of sophisticated cues, induding an inborm map of the night sky and the pull of the earth's magnetic field. How the birds use their instruments' remains unknow, but one thing is clear: they see the world with a superior sensory perception to ours. Most small birds migrate at night and take their direction from the position of the setting sun. However, as well as seeing the sun go down, they also seem to see the plane of polarized light caused by it, which calibrates their compass. Travelling at night provides other benefits. Daytime predators are avoided and the danger of dehydration due to

flying for long periods in warm, sunlit skies is reduced. Furthermore, at night the air is generally cool and less turbulent and so conducive to sustained, stable flight.

Nevertheless, all journeys involve considerable risk, and part of the skill in arriving safely is setting off at the right time. Time means accurate weather

forecasting, and tilizing favorable winds. Birds are adept at both, and, in laboratory tests, some have been shown on detect the minute difference in

barometric pressure between the floor and ceiling ofa room. Often birds react to weather changes before there is any visible sign of them. Lapwings, which

feed on grassland, flee west from the Netherlands to the British Isles, France and Spain at the onset of a cold snap. When the ground surface freezes the

birds could starve. Yet they return to Holland ahead of a thaw, their arrival linked to a pressure change presaging an improvement in the weather.

In one instance a Welsh Manx shearwater carried to America and released was back in its burrow on Skokholm Island, off the Pembrokeshire cast, one day

before a letter announcing its release! Conversely, each autumn a small number of North American birds are blown cross the Atlantic by fast-moving westerly tail winds. Not only do they arrive safely in Europe, but, based on ringing evidence, some make it back to North America the following spring,after probably spending the winter with European migrants in sunny African

climes.

14-16为完成句子题

14. Despise some difculties, birds finally can find the destinations

15. Birds can use different ways to help them go back home such as observing

sun.

16.暂缺

17-18为判断题暂缺

19-22为匹配题

which paragraph contains the idea

19. the methodology of examining birds' ability to find home

20. the distance can affect the birds find home

21. some aspects of physical features in humans and birds