[雅思机经]2017年7月29日雅思阅读真题回顾

考试日期

2017年7月29日

Reading Passage 1

Title

Going bananas

Question types

Complete sentences 3题

Matching（人名理论配对） 7题

TRUE / FALSE / NOT GIVEN 3题

文章内容回顾

香蕉将在十年的时间内消失及分析造成这一问题的原因。

文章内容回顾

A  The world’s favourite fruit could disappear forever in 10 years’ time. The banana is among the world’s oldest crops. Agricultural scientists believe that the first edible banana was discovered around ten thousand years ago. It has been at an evolutionary stand still ever since it was first propagated in the jungles of South-East Asia at the end of the last ice age. Normally the wild banana, a giant jungle herb a mass of hard seeds that make the fruit virtually inedible. But now and then, hunter-gatherers must have discovered rare mutant plants that produced seed-less, edible fruits. Geneticists now know that the vast majority of these soft-fruited plants resulted from genetic accidents that gave their cells three copies of each chromosome instead of the usual two. This imbalance prevents seeds and pollen from developing normally, rendering the mutant plants sterile. And that is why some scientists believe the world’s most popular fruit could be doomed. It lacks the genetic diversity to fight off pests and diseases that are invading the banana plantations of Central America and the small-holdings of Africa and Asia alike.

B  In some ways, the banana today resembles the potato before blight brought famine to Ireland a century and a half ago. But it holds a lesson for other crops, too, says Emile Frison, top banana at the International Network for the Improvement of Banana an4 Plantain in Montpellier, France. The state of the banana, Frison warns, can teach a broader lesson the increasing standardisation of food crops round the world is threatening their ability to adapt and survive.

C  The first Stone Age plantbreeders cultivated these sterile freaks by replanting cuttings from their stems. And the descendants of those original cuttings are the bananas we still eat today. Each is a virtual clone, almost devoid of genetic diversity. And that uniformity makes it ripe for disease like no other crop on Earth. Traditional varieties of sexually reproducing crops have always had a much broader genetic base, and the genes will recombine in new arrangements in each generation. This gives them much greater flexibility in evolving responses to disease-and far more genetic resources to draw on in the face of an attack. But that advantage is fading fast, as growers increasingly plant the same few, high-yielding varieties. Plant breeders work feverishly to maintain resistance in these standardized crops. Should these efforts falter, yields of even the most productive crop could swiftly crash. When some pest or disease comes along, severe epidemics can occur, says Geoff Hawtin, director of the Rome-based International Plant Genetic Resources Institute.

D  The banana is an excellent case in point. Until the 1950s, one variety, the Gros Michel, dominated the world’s commercial banana business. Found by French botanists in Asian the 1820s, the Gros Michel was by all accounts a fine banana, richer and sweeter than today’s standard banana and without the latter/s bitter aftertaste when green. But it was vulnerable to a soil fungus that produced a wilt known as Panama disease. Once the fungus gets into the soil it remains there for many years. There is nothing farmers can do. Even chemical spraying won’t get rid of it, says Rodomiro Ortiz, director of the Inter-national Institute for Tropical Agriculture in Ibadan, Nigeria. So plantation owners played a running game, abandoning infested fields and moving so clean land-until they ran out of clean land in the 1950s and had to abandon the Gros Michel. Its successor, and still the reigning commercial king, is the Cavendish banana, a 19th-century British discovery from southern China. The Cavendish is resistant to Panama disease and, as a result, it literally saved the international banana industry. During the 1960s, it replaced the Gros Michel on supermarket shelves. If you buy a banana today, it is almost certainly a Cavendish. But even so, it is a minority in the world’s banana crop.

E  Half a billion people in Asia and Africa depend on bananas. Bananas provide the largest source of calories and are eaten daily. Its name is synonymous with food. But the day of reckoning may be coming for the Cavendish and its indigenous kin. Another fungal disease, black Sigatoka, has become a global epidemic since its first appearance in Fiji in 1963. Left to itself, black Sigatoka-which causes brown wounds on leaves and pre-mature fruit ripening cuts fruit yields by 50 to 70 per cent and reduces the productive lifetime of banana plants from 30 years to as little as 2 or 3. Commercial growers keep Sigatoka at bay by a massive chemical assault. Forty sprayings of fungicide a year is typical. But despite the fungicides, diseases such as black Sigatoka are getting more and more      difficult to control. As soon as you bring in a new fungicide, they develop resistance, says Frison. One thing we can be sure of is that the Sigatoka won’t lose in this battle. Poor farmers, who cannot afford chemicals, have it even worse. They can do little more than watch their plants die.  Most of the banana fields in Amazonia have already   been destroyed by the disease, says Luadir Gasparotto, Brazil’s leading banana pathologist with the government research agency EMBRAPA. Production is likely to fall by 70 percent as the disease spreads, he predicts. The only option will be to find a new variety.

F  But how? Almost all edible varieties are susceptible to the diseases, so growers cannot simply change to a different banana. With most crops, such a threat would unleash an army of breeders, scouring the world for resistant relatives whose traits they can breed into commercial varieties. Not so with the banana. Because all edible varieties are sterile, bringing in new genetic traits to help cope with pests and diseases is nearly impossible. Nearly, but not totally. Very rarely, a sterile banana will experience a genetic accident that allows an almost normal seed to develop, giving breeders a tiny window for improvement. Breeders at the Honduran Foundation of Agricultural Research have tried to exploit this to create disease-resistant varieties. Further backcrossing with wild bananas yielded a new seedless banana resistant to both black Sigatoka and Panama disease.

G  Neither Western supermarket consumers nor peasant growers like the new hybrid. Some accuse it of tasting more like an apple than a banana. Not surprisingly, the majority of plant breeders have till now turned their backs on the banana and got to work on easier plants. And commercial banana companies are now washing their hands of the whole breeding effort, preferring to fund a search for new fungicides instead. We supported a breeding programme for 40 years, but it wasn’t able to develop an alternative to Cavendish. It was very expensive and we got nothing back, says Ronald Romero, head of research at Chiquita, one of the Big Three companies that dominate the international banana trade.

H  Last year, a global consortium of scientists led by Frison announced plans to sequence the banana genome within five years. It would be the first edible fruit to be sequenced. Well, almost edible. The group will actually be sequencing inedible wild bananas from East Asia because many of these are resistant to black Sigatoka. If they can pinpoint the genes that help these wild varieties to resist black Sigatoka, the protective genes could be introduced into laboratory tissue cultures of cells from edible varieties. These could then be propagated into new, resistant plants and passed on to farmers.

I  It sounds promising, but the big banana companies have, until now, refused to get involved in GM research for fear of alienating their customers. Biotechnology is extremely Expensive and there are serious questions about consumer acceptance, says David McLaughlin, Chiquita’s senior director for environmental affairs. With scant funding from the companies, the banana genome researchers are focusing on the other end of the spectrum. Even if they can identify the crucial genes, they will be a long way from developing new varieties that smallholders will find suitable  and  affordable. But whatever biotechnology’s academic interest, it is the only hope for the banana. Without banana production worldwide will head into a tailspin. We may even see the extinction of the banana as both a lifesaver for hungry and impoverished Africans and as the most popular product on the world’s supermarket shelves.

1-3 Complete sentences (NO MORE THAN THREE WORDS.)

1. Banana was first eaten as a fruit by humans almost ten thousand years ago.

2. Banana was first planted in South-East Asia.

3. The wild banana can’t be eaten because of (hard) seeds.

4-10 Matching（人名理论配对）

N.B. You may use any letter more than once.

A. Rodomiro                              B. David Mclaughlin

C. Emile Frison                         D. Ronald Romero

E. Luadir Gasparotto                 F. Geoff Hawtin

4. Pest invasion may seriously damage banana industry.  F

5. The effect of fungal infection in soil is often long-lasting.  A

6. A commercial manufacturer gave up on breeding bananas for disease resistant species.  D

7. Banana disease may develop resistance to chemical sprays.  C

8. A banana disease has destroyed a large number of banana plantations.  E

9. Consumers would not accept genetically altered crop.  B

10. Lessons can be learned from bananas for other crops.  C

11-13 TRUE / FALSE / NOT GIVEN

11. Banana is the oldest known fruit.  NOT GIVEN

12. Gros Michel is still being used as a commercial product.  FALSE

13. Banana is a main food in some countries.  TRUE

题型难度分析

第一篇的题型包括填空题，人名理论配对题以及判断题。本篇文章填空和判断的难度不大，人名理论配对个别题目略难。

题型技巧分析

判断题(TRUE / FALSE / NOT GIVEN)是雅思阅读中的一种经典题型，也是一直以来非常重要的题型。判断题是一种细节题，有顺序原则。

解题思路：

1. 找出题目中的定位词，考点词（比较级，最高级，程度副词，特殊形容词，是非考点词，绝对化的词），找出题目在原文中的出处，注意顺序性原则，且一次要定位两道题目。

2. 根据下列原则和规律，确定正确答案：

TRUE/YES: 题目与原文描述含义相符

FALSE/NO: 题目与原文描述含义相悖

NOT GIVEN: 原文中所提供的信息不足以用来判断题目正误

PS: 注意要审题，TRUE / FALSE / NOT GIVEN和YES / NO / NOT GIVEN不能写混。

剑桥雅思推荐原文练习

剑5 Test 4 Passage 2

Reading Passage 2

Title

The Lost City

Question types

Matching（段落信息配对） 4题

Summary Completion 8题

Multiple Choice 1题

文章内容回顾

消失的城市。

相关英文原文阅读

Thanks to modern remote-sensing techniques, a ruined city in Turkey is slowly revealing itself as one of the greatest and most mysterious cities of the ancient world. Sally Palmer uncovers more.

A  The low granite mountain, known as Kerkencs Dag, juts from the northern edge of the C'appadocian plain in Turkey. Sprawled over the mountainside are the rums of an enormous city, contained by crumbling defensive walls seven kilometers long. Many respected archaeologists believe these are the remains of the fabled city of Plena, the sixth-century BC stronghold of the Mcdes that the Greek historian Herodotus described in his famous work The Histories. The short-lived city came under Median control and only fifty years later was sacked, burned and its strong stone walls destroyed.

B  British archeologist Dr Geoffrey Summer* has spent ten years studying the site. Excavating the ruins is a challenge because of the vast area they cover. The 7 km perimeter walls run around a site covering 271 hectares. Dr Summers quickly realised it would take far too long to excavate the site using traditional techniques alone. So he decided to use modem technology as well to map the entire site, both above and beneath the surface, to locate the most interesting areas and priorities to start digging.

C  In 1993. Dr Summers hired a special hand held balloon with a remote-controlled camera attached. He walked over the entire site holding the balloon and taking photos. Then one afternoon, he rented a hot-air balloon and floated over the site, taking yet more pictures By the end of the 1994 season. Dr Summers and his team had a jigsaw of aerial photographs of the whole site. The next stage was to u&c remote sensing, which would let them work out what lay below the intriguing outlines and ruined walls. "Archaeology is a discipline that lends itself very well to remote sensing because it revolves around space," says Scott Brantmg, an associated director of the project, lie started working with Dr Summers in 1995.

D  The project used two remote sensing techniques. The first is magnetometry which works on the principle thai magnetic fields al the surface of the Earth are influenced by what it buried beneath. It measures localised variations in the direction and intensity of this magnetic field. "The Earth's magnetic field can vary from place to placc, depending on what happened there in the past." says Branting. "if something containing iron oxide was heavily burnt, by natural or human actions, the iron particles in it can be permanently reoriented, like a compass needle, to align with the Earth's magnetic field present at that point in time and space." The magnetometer detects differences in the orientations and intensities of these iron particles from the present-day magnetic field and uses them to produce an image of what lies below ground.

E  Kerienes Dag lends itself particularly well to magnctomctry because it was all burnt at once in a savage fire. In places the heat was sufficient to turn sandstone to glass and to melt granite. The fire was so hot that there were strong magnetic signanires set to the Earth's magnetic field from the time - around 547 BC - resulting in extremely clear pictures. Furthermore, the city was never rebuilt, "if you have multiple layers confusing picture, because you have different walls from different periods giving signatures that all go in different directions," says Branting. "We only have one going down about 1.5 meters, so we can get a good picture of this fairly short-lived city."

F  The other main sub-surface mapping technique, which is still being used at the site, is resistivity. This technique measures the way electrical pulses arc conducted through sub- surface soil. It's done by shooting pulses into the ground through a thin metal probe. Different materials have different electrical conductivity. For example, stone and mudbnek arc poor conductors, but looser, damp soil conducts very well. By walking around the site and taking about four readings per metre, it is possible to get a detailed idea of what is where beneath the surface. The teams then build up picnires of walls, hearths and other remains. "It helps a lot if it has rained, because the electrical pulse can get through more easily," says Branting. "Then if something is more resistant, it really shows up." This is one of the reasons that the project has a spring season, when most of the resistivity work is done. Unfortunately testing resistivity is a lot slower than magnetometry. "If we did resistivity over the whole site it would take about 100 years," says Branting. Consequently, the team is concentrating on areas where they want to clarify pictures from the magnetometry.

G  Remote sensing does not reveal everything about Kerkenes Dag, but it shows the most interesting sub-surface areas of the site. The archaeologists can then excavate these using traditional techniques. One surprise came when they dug out one of the fates in the defensive walls. "Our observations in early seasons led us to assume that wall, such as would be found at most other cities in the Ancient Near East," says Dr Summers. "When we started to excavate we were staggered to discover that the walls were made entirely from stone and that the gate would have stood at least ten metres high. After ten years of study, Pteria is gradually giving up its secrets."

14-17 Matching（段落信息配对题）

14. The reason why various investigative methods are introduced. B

15. An example of an unexpected discovery.  G

16. The methods to survey the surface of the site from above.  C

17. The reason why experts want to study the site.  A

18-25 Summary (no more than THREE words)

Exploring the Ancient City of Pteria

The relevant work was done ten year ago. To begin with, experts took photos of the site from the ground and then from a distance in a 18 hot-air ballon. To find out what lay below the surface, they used two leading techniques. One was magnetometer, which identifies changes in the magnetic field. These changes occur when the 19 iron particles in buried structures have changed direction as a result of great heat. They match with the magnetic field, which is similar to a 20 compass/compass needle.

The other one was resistivity, which uses a 21 thin metal probe to fire electrical pulses into the earth. The principle is that building materials like 22 mudbrick and stone do not conduct electricity well, while 23 looser damp soil does this much better. Archaeologists preferred to use this technique during the 24 spring season, when conditions are more favourable. Resistivity is mainly being used to 25 clarify some images generated by the magnetometer.

26. Multiple Choice

26. How do modern remote-sensing techniques help at the site?

B. They bring parts of the site into light so that key areas can be researched further.

题型难度分析

本篇文章题目难度较上一篇有所增加，为三篇中最难的一篇，段落信息配对题有一定难度，要注意此种题型在题干上的乱序性。

题型技巧分析

段落信息配对题是雅思考试中比较难的题型，我们来分析一下这类题目的做题技巧与特点：

1. 彻底同义转换

和其它题型不同的是，这种题型是对原文一句话或者一段话进行的彻底同义转换，个别甚至是高度概括，因此几乎不存在任何定位词，因此不能根据定位词到原文中定位答案。考生必须具备非常强的语言理解能力，才能快速识别出文章信息和段落信息的相似之处，从而找到答案。

2. 完全乱序

由于这种题型是要求把细节信息与所在的段落进行配对，因此是绝对打乱顺序出题的。

3. 部分题目存在重复选项

在雅思阅读中，段落细节配对题以两种形式出现：一种是每个选项只能用一次；另外一种题型，在Instruction的最后一句往往有这样的提示：NB You may use any letter more than once. 如果出现这样的提示，则说明某些段落可以重复选用。

剑桥雅思推荐原文练习

剑9 Test 2 Passage 1

Reading Passage 3

Title

Thinking Small: Globalization and Choice of Technology

Question types

Summary Completion 5题

Multiple Choice 3题

YES / NO / NOT GIVEN 6题

文章内容回顾

在目前经济全球化的情况下，引进先进技术是热门的话题。虽然发展中国家需要引进先进的技术，但他们缺乏人力、技能、资源，如石油、天然气等等。信息技术被认为是发展经济的好办法。在一些发展中国家，信息可能有一些好处，所以在发展中国家，可以适当地发展微小型企业，并同时发展当地产业。

27-30 Summary Completion

27. leader

28. automation

29. skill

30. capital

31. resources

32-34 Multiple Choice

32. 选：B. has had an impact on the choice of local people

33. 选：A. technology will not provide an equal society

34. 选：C. is more helpful in rural areas

35-40 YES / NO / NOT GIVEN

35. YES

36. NOT GIVEN

37. YES

38. NO

39. NO

40. YES

题型难度分析

本文难度适中，单选题难度稍大。

题型技巧分析

单选题：由题干和4个选项构成，基本题干可以用来定位，如果题干无法准确定位，从选项反推即可。正确选项一般是对文章的改写，注意同义转换，错误的选项有的是干扰项，非常容易误选，也有的是文章未提及的内容，应排除。

剑桥雅思推荐原文练习

剑11 Test 2 Passage 3

考试趋势分析和备考指导：

本场雅思阅读考试2旧1新；出现了段落信息配对题和人名配对题，没有出现LOH；第一篇和第三篇难度系数不是很大。剩余题型中，判断题和填空题依旧为主流题型，建议考生在最近的考试中要格外重视这两种题型。另外上文提到过的本场考试没有出现的LOH题型也是参加下一场考试的考生需要特别关注的。