劍橋雅思閱讀7原文難度解析(test3)
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劍橋雅思閱讀7原文(test3)
READING PASSAGE 1
You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Ant Intelligence
When we think of intelligent members of the animal kingdom, the creatures that spring immediately to mind are apes and monkeys. But in fact the social lives of some members of the insect kingdom are sufficiently complex to suggest more than a hint of intelligence. Among these, the world of the ant has come in for considerable scrutiny lately, and the idea that ants demonstrate sparks of cognition has certainly not been rejected by those involved in these investigations.
Ants store food, repel attackers and use chemical signals to contact one another in case of attack. Such chemical communication can be compared to the human use of visual and auditory channels (as in religious chants, advertising images and jingles, political slogans and martial music) to arouse and propagate moods and attitudes. The biologist Lewis Thomas wrote, ‘Ants are so much like human beings as to be an embarrassment. They farm fungi, raise aphids_as livestock, launch armies to war, use chemical sprays to alarm and confuse enemies, capture slaves, engage in child labour, exchange information ceaselessly. They do everything but watch television.’
However, in ants there is no cultural transmission — everything must be encoded in the genes — whereas in humans the opposite is true. Only basic instincts are carried in the genes of a newborn baby, other skills being learned from others in the community as the child grows up. It may seem that this cultural continuity gives us a huge advantage over ants. They have never mastered fire nor progressed. Their fungus farming and aphid herding crafts are sophisticated when compared to the agricultural skills of humans five thousand years ago but have been totally overtaken by modern human agribusiness.
Or have they? The farming methods of ants are at least sustainable. They do not ruin environments or use enormous amounts of energy. Moreover, recent evidence suggests that the crop farming of ants may be more sophisticated and adaptable than was thought.
Ants were farmers fifty million years before humans were. Ants can’t digest the cellulose in leaves — but some fungi can. The ants therefore cultivate these fungi in their nests, bringing them leaves to feed on, and then use them as a source of food. Farmer ants secrete antibiotics to control other fungi that might act as ‘weeds’, and spread waste to fertilise the crop.
It was once thought that the fungus that ants cultivate was a single type that they had propagated, essentially unchanged from the distant past. Not so. Ulrich Mueller of Maryland and his colleagues genetically screened 862 different types of fungi taken from ants’ nests. These turned out to be highly diverse: it seems that ants are continually domesticating new species. Even more impressively, DNA analysis of the fungi suggests that the ants improve or modify the fungi by regularly swapping and sharing strains with neighbouring ant colonies.
Whereas prehistoric man had no exposure to urban lifestyles — the forcing house of intelligence — the evidence suggests that ants have lived in urban settings for close on a hundred million years, developing and maintaining underground cities of specialised chambers and tunnels.
When we survey Mexico City, Tokyo, Los Angeles, we are amazed at what has been accomplished by humans. Yet Hoelldobler and Wilson’s magnificent work for ant lovers, The Ants, describes a supercolony of the ant Formica yessensis on the Ishikari Coast of Hokkaido. This ‘megalopolis’ was reported to be composed of 360 million workers and a million queens living in 4,500 interconnected nests across a territory of 2.7 square kilometres.
Such enduring and intricately meshed levels of technical achievement outstrip by far anything achieved by our distant ancestors. We hail as masterpieces the cave paintings in southern France and elsewhere, dating back some 20,000 years. Ant societies existed in something like their present form more than seventy million years ago. Beside this, prehistoric man looks technologically primitive. Is this then some kind of intelligence, albeit of a different kind?
Research conducted at Oxford, Sussex and Zurich Universities has shown that when desert ants return from a foraging trip, they navigate by integrating bearings and distances, which they continuously update in their heads. They combine the evidence of visual landmarks with a mental library of local directions, all within a framework which is consulted and updated. So ants can learn too.
And in a twelve-year programme of work, Ryabko and Reznikova have found evidence that ants can transmit very complex messages. Scouts who had located food in a maze returned to mobilise their foraging teams. They engaged in contact sessions, at the end of which the scout was removed in order to observe what her team might do. Often the foragers proceeded to the exact spot in the maze where the food had been. Elaborate precautions were taken to prevent the foraging team using odour clues. Discussion now centres on whether the route through the maze is communicated as a ‘left-right’ sequence of turns or as a ‘compass bearing and distance’ message.
During the course of this exhaustive study, Reznikova has grown so attached to her laboratory ants that she feels she knows them as individuals — even without the paint spots used to mark them. It’s no surprise that Edward Wilson, in his essay, ‘In the company of ants’, advises readers who ask what to do with the ants in their kitchen to: ‘Watch where you step. Be careful of little lives.’
Questions 1-6
Do the following statements agree with the information given in Reading Passage 1?
In boxes 1-6 on your answer sheet, write
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
1 Ants use the same channels of communication as humans do.
2 City life is one factor that encourages the development of intelligence.
3 Ants can build large cities more quickly than humans do.
4 Some ants can find their way by making calculations based on distance and position.
5 In one experiment, foraging teams were able to use their sense of smell to find food.
6 The essay, ‘In the company of ants’, explores ant communication.
Questions 7-13
Complete the summary using the list of words, A-O, below.
Write the correct letter, A-O, in boxes 7-13 on your answer sheet.
Ants as farmers
Ants have sophisticated methods of farming, including herding livestock and growing crops, which are in many ways similar to those used in human agriculture. The ants cultivate a large number of different species of edible fungi which convert a form which they can digest. They use their own natural weed-killers and also use unwanted materials as 9.............. . Genetic analysis shows they constantly upgrade these fungi by developing new species and by ies with neighbouring ant colonies. In fact, the farming methods of ants could be said to be more advanced than human agribusiness, since they use ods, they do not affect the do not waste 13.............. .
A aphids B agricultural C cellulose D exchanging
E energy F fertilizers G food H fungi
I growing J interbreeding K natural L other speces
M secretions N sustainable O environment
READING PASSAGE 2
You should spend about 20 minutes on Questions 14-26, which are based on Reading Passage 2 on the following pages.
Questions 14-19
Reading Passage 2 has seven sections, A-G.
Choose the correct headings for sections A-F from the list of headings below.
Write the correct number, i-x, in boxes 14-19 on your answer sheet.
List of Headings
i The results of the research into blood-variants
ii Dental evidence
iii Greenberg’s analysis of the dental and linguistic evidence
iv Developments in the methods used to study early population movements
v Indian migration from Canada to the U.S.A.
vi Further genetic evidence relating to the three-wave theory
vii Long-standing questions about prehistoric migration to America
viii Conflicting views of the three-wave theory, based on non-genetic evidence
ix Questions about the causes of prehistoric migration to America
x How analysis of blood-variants measures the closeness of the relationship between different populations
14 Section A
15 Section B
16 Section C
17 Section D
18 Section E
19 Section F
Example Answer
Section G viii
Population movements and genetics
A Study of the origins and distribution of human populations used to be based on archaeological and fossil evidence. A number of techniques developed since the 1950s, however, have placed the study of these subjects on a sounder and more objective footing. The best information on early population movements is now being obtained from the ‘archaeology of the living body’, the clues to be found in genetic material.
B Recent work on the problem of when people first entered the Americas is an example of the value of these new techniques. North-east Asia and Siberia have long been accepted as the launching ground for the first human colonisers of the New World1. But was there one major wave of migration across the Bering Strait into the Americas, or several? And when did this event, or events, take place? In recent years, new clues have come from research into genetics, including the distribution of genetic markers in modern Native Americans2.
C An important project, led by the biological anthropologist Robert Williams, focused on the variants (called Gm allotypes) of one particular protein — immunoglobin G — found in the fluid portion of human blood. All proteins ‘drift’, or produce variants, over the generations, and members of an interbreeding human population will share a set of such variants. Thus, by comparing the Gm allotypes of two different populations (e.g. two Indian tribes), one can establish their genetic ‘distance’, which itself can be calibrated to give an indication of the length of time since these populations last interbred.
D Williams and his colleagues sampled the blood of over 5,000 American Indians in western North America during a twenty-year period. They found that their Gm allotypes could be divided into two groups, one of which also corresponded to the genetic typing of Central and South American Indians. Other tests showed that the Inuit (or Eskimo) and Aleut3 formed a third group. From this evidence it was deduced that there had been three major waves of migration across the Bering Strait. The first, Paleo-lndian, wave more than 15,000 years ago was ancestral to all Central and South American Indians. The second wave, about 14,000-12,000 years ago, brought Na-Dene hunters, ancestors of the Navajo and Apache (who only migrated south from Canada about 600 or 700 years ago). The third wave, perhaps 10,000 or 9,000 years ago, saw the migration from North-east Asia of groups ancestral to the modern Eskimo and Aleut.
E How far does other research support these conclusion? Geneticist Douglas Wallace has studied mitochondrial DNA4 in blood samples from three widely separated Native American groups: Pima-Papago Indians in Arizona, Maya Indians on the Yucatan peninsula, Mexico, and Ticuna Indians in the Upper Amazon region of Brazil. As would have been predicted by Robert Williams’s work, all three groups appear to be descended from the same ancestral (Paleo-lndian) population.
F There are two other kinds of research that have thrown some light on the origins of the Native American population; they involve the study of teeth and of languages. The biological anthropologist Christy Turner is an expert in the analysis of changing physical characteristics in human teeth. He argues that tooth crowns and roots5 have a high genetic component, minimally affected by environmental and other factors. Studies carried out by Turner of many thousands of New and Old World specimens, both ancient and modern, suggest that the majority of prehistoric Americans are linked to Northern Asian populations by crown and root traits such as incisor6 shoveling (a scooping out on one or both surfaces of the tooth), single-rooted upper first premolars6 and triple-rooted lower first molars6.
According to Turner, this ties in with the idea of a single Paleo-lndian migration out of North Asia, which he sets at before 14,000 years ago by calibrating rates of dental micro-evolution. Tooth analyses also suggest that there were two later migrations of Na-Denes and Eskimo-Aleut.
G The linguist Joseph Greenberg has, since the 1950s, argued that all Native American languages belong to a single ‘Amerind’ family, except for Na-Dene and Eskimo-Aleut — a view that gives credence to the idea of three main migrations. Greenberg is in a minority among fellow linguists, most of whom favour the notion of a great many waves of migration to account for the more than 1,000 languages spoken at one time by American Indians. But there is no doubt that the new genetic and dental evidence provides strong backing for Greenberg’s view. Dates given for the migrations should nevertheless be treated with caution, except where supported by hard archaeological evidence.
1 New World: the American continent, as opposed to the so-called Old World of Europe, Asia and Africa
2 modern Native American: an American descended from the groups that were native to America
3 Inuit and Aleut: two of the ethnic groups native to the northern regions of North America (i.e. northern Canada and Greenland)
4 DNA: the substance in which genetic information is stored
5 crown/root: parts of the tooth
6 incisor/premolar/molar: kinds of teeth
Questions 20 and 21
The discussion of Williams’s research indicates the periods at which early people are thought to have migrated along certain routes. There are six routes, A-F, marked on map below.
Complete the table below.
Write the correct letter, A-F, in boxes 20 and 21 on your answer sheet.
Route Period (number of years ago)
20.................. 15,000 or more
21.................. 600 to 700
Early Population Movement to the Americas
Questions 22-25
Reading Passage 2 refers to the three-wave theory of early migration to the Americas. It also suggests in which of these three waves the ancestors of various groups of modern native Americans first reached the continent.
Classify the groups named in the table below as originating from
A the first wave
B the second wave
C the third wave
Write the correct letter, A, B or C, in boxes 22-25 on your answer sheet.
Name of group Wave number
Inuit 22..................
Apache 23..................
Pima-Papago 24..................
Ticuna 25..................
Question 26
Choose the correct letter, A, B, C or D.
Write the correct letter in box 26 on your answer sheet.
Christy Turner’s research involved the examination of
A teeth from both prehistoric and modern Americans and Asians.
B thousands of people who live in either the New or the Old World.
C dental specimens from the majority of prehistoric Americans.
D the eating habits of American and Asian populations.
READING PASSAGE 3
You should spend about 20 minutes on Questions 27-40, which are based on Reading Passage 3 below.
Forests are one of the main elements of our natural heritage. The decline of Europe’s forests over the last decade and a half has led to an increasing awareness and understanding of the serious imbalances which threaten them. European countries are becoming increasingly concerned by major threats to European forests, threats which know no frontiers other than those of geography or climate: air pollution, soil deterioration, the increasing number of forest fires and sometimes even the mismanagement of our woodland and forest heritage. There has been a growing awareness of the need for countries to get together to co-ordinate their policies. In December 1990, Strasbourg hosted the first Ministerial Conference on the protection of Europe’s forests. The conference brought together 31 countries from both Western and Eastern Europe. The topics discussed included the coordinated study of the destruction of forests, as well as how to combat forest fires and the extension of European research programs on the forest ecosystem. The preparatory work for the conference had been undertaken at two meetings of experts. Their initial task was to decide which of the many forest problems of concern to Europe involved the largest number of countries and might be the subject of joint action. Those confined to particular geographical areas, such as countries bordering the Mediterranean or the Nordic countries therefore had to be discarded. However, this does not mean that in future they will be ignored.
As a whole, European countries see forests as performing a triple function: biological, economic and recreational. The first is to act as a ‘green lung’ for our planet; by means of photosynthesis, forests produce oxygen through the transformation of solar energy, thus fulfilling what for humans is the essential role of an immense, non-polluting power plant. At the same time, forests provide raw materials for human activities through their constantly renewed production of wood. Finally, they offer those condemned to spend five days a week in an urban environment an unrivalled area of freedom to unwind and take part in a range of leisure activities, such as hunting, riding and hiking. The economic importance of forests has been understood since the dawn of man — wood was the first fuel. The other aspects have been recognised only for a few centuries but they are becoming more and more important. Hence, there is a real concern throughout Europe about the damage to the forest environment which threatens these three basic roles.
The myth of the ‘natural’ forest has survived, yet there are effectively no remaining ‘primary’ forests in Europe. All European forests are artificial, having been adapted and exploited by man for thousands of years. This means that a forest policy is vital, that it must transcend national frontiers and generations of people, and that it must allow for the inevitable changes that take place in the forests, in needs, and hence in policy. The Strasbourg conference was one of the first events on such a scale to reach this conclusion. A general declaration was made that ‘a central place in any ecologically coherent forest policy must be given to continuity over time and to the possible effects of unforeseen events, to ensure that the full potential of these forests is maintained’.
That general declaration was accompanied by six detailed resolutions to assist national policy-making. The first proposes the extension and systematisation of surveillance sites to monitor forest decline. Forest decline is still poorly understood but leads to the loss of a high proportion of a tree’s needles or leaves. The entire continent and the majority of species are now affected: between 30% and 50% of the tree population. The condition appears to result from the cumulative effect of a number of factors, with atmospheric pollutants the principal culprits. Compounds of nitrogen and sulphur dioxide should be particularly closely watched. However, their effects are probably accentuated by climatic factors, such as drought and hard winters, or soil imbalances such as soil acidification, which damages the roots. The second resolution concentrates on the need to preserve the genetic diversity of European forests. The aim is to reverse the decline in the number of tree species or at least to preserve the ‘genetic material’ of all of them. Although forest fires do not affect all of Europe to the same extent, the amount of damage caused the experts to propose as the third resolution that the Strasbourg conference consider the establishment of a European databank on the subject. All information used in the development of national preventative policies would become generally available. The subject of the fourth resolution discussed by the ministers was mountain forests. In Europe, it is undoubtedly the mountain ecosystem which has changed most rapidly and is most at risk. A thinly scattered permanent population and development of leisure activities, particularly skiing, have resulted in significant long-term changes to the local ecosystems. Proposed developments include a preferential research program on mountain forests. The fifth resolution relaunched the European research network on the physiology of trees, called Eurosilva. Eurosilva should support joint European research on tree diseases and their physiological and biochemical aspects. Each country concerned could increase the number of scholarships and other financial support for doctoral theses and research projects in this area. Finally, the conference established the framework for a European research network on forest ecosystems. This would also involve harmonising activities in individual countries as well as identifying a number of priority research topics relating to the protection of forests. The Strasbourg conference’s main concern was to provide for the future. This was the initial motivation, one now shared by all 31 participants representing 31 European countries. Their final text commits them to on-going discussion between government representatives with responsibility for forests.
Questions 27-33
Do the following statements agree with the information given in Reading Passage 3?
In boxes 27-33 on your answer sheet, write
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
27 Forest problems of Mediterranean countries are to be discussed at the next meeting or experts.
28 Problems in Nordic countries were excluded because they are outside the European Economic Community.
29 Forests are a renewable source of raw material.
30 The biological functions of forests were recognized only in the twentieth century.
31 Natural forests still exist in parts of Europe.
32 Forest policy should be limited by national boundaries.
33 The Strasbourg conference decided that a forest policy must allow for the possibility of change.
Questions 34-39
Look at the following statements issued by the conference.
Which six of the following statements, A-J, refer to the resolutions that were issued?
Match the statements with the appropriate resolutions (Questions 34-39).
Write the correct letter, A-J, in boxes 34-39 on your answer sheet.
A All kinds of species of trees should be preserved.
B Fragile mountain forests should be given priority in research programs.
C The surviving natural forests of Europe de not need priority treatment.
D Research is to be better co-ordinated throughout Europe.
E Information on forest fires should be collected and shared.
F Loss of leaves from trees should be more extensively and carefully monitored.
G Resources should be allocated to research into tree diseases.
H Skiing should be encouraged in thinly populated areas.
I Soil imbalances such as acidification should be treated with compounds of nitrogen and sulphur.
J Information is to be systematically gathered on any decline in the condition of forests.
34 Resolution 1
35 Resolution 2
36 Resolution 3
37 Resolution 4
38 Resolution 5
39 Resolution 6
Question 40
Choose the correct letter, A, B, C or D.
Write the correct letter in box 40 on your answer sheet.
40 What is the best title for Reading Passage 3?
A The biological, economic and recreational role of forests
B Plans to protect the forests of Europe
C The priority of European research into ecosystems
D Proposals for a world-wide policy on forest management
劍橋雅思閱讀7原文參考譯文(test3)
TEST 3 PASSAGE 1 參考譯文：
螞蟻智能
每當我們想到動物界的智能成員時，頭腦中立刻出現的會是猿和猴子。事實上，在昆蟲界，某些成員社會生活的複雜程度顯示出了相當程度的智能。其中螞蟻世界就在最近成了主要的觀察對象螞蟻顯示出一定認知力的觀點也得到了研?a href="">咳嗽鋇目隙ā?/p>
螞蟻儲存食物，反擊外敵，在攻擊時用化學信號互相聯繫。此類化學信號交流可與人類使用視覺和聽覺途徑(如聖歌、廣告形象、鈴聲、政治標語以及軍樂)來激發情緒和傳遞理念的行爲相媲美。生物學家 Lewis Thomas寫道：“螞蟻和人類是如此的相似，都讓我們覺得自愧不如。它們培育真菌，把蚜蟲作爲家畜來飼養，調配軍隊作戰，用化學氣霧發出替告和迷惑敵人，俘虜奴隸，忙於育嬰，不停地交流信息。除了不看電視它們什麼都做。”
然而，螞蟻的世界裏沒有文化的傳播——所有的技能都必須存儲在基因裏——而人類的情況卻恰恰相反。人類新生兒的基因裏只有基本的本能，其他技能則是在成長過程中從社會其他成員身上學習所得。看起來這種文化傳承使我們與螞蟻相比具有巨大的優勢。它們從未掌握用火技術，也不知發展爲何物，它們培育真菌、飼養蚜蟲的技術和五千年前的人類農耕技術相比還算成熟，但卻被人類現代的農業綜合企業遠遠超越。
那麼螞蟻真的被人類超越了麼?螞蟻的農耕方式至少是可持續性的。它們不會破壞環境，也不需要使用大量能源。而且，最近的證據表明，螞蟻的農耕方式可能比過去我們所認爲的還要成熟和靈活。
螞蟻早於人類5000萬年就已成爲農夫。它們不能消化葉子中的纖維素，但是某些真菌可以。因此螞蟻在巢穴裏培育這些真菌，讓它們以葉子爲食，而真菌則成爲螞蟻的食物來源。螞蟻農夫們分泌抗生素去控制其他可能成爲“雜草”的真菌，還會播撒廢料來給作物施肥。
曾經有觀點認爲螞蟻培育的真菌只是它們繁殖的單一品種，長久以來都沒有本質的改變。其實不然。馬里蘭州的Ulrich Mueller和他的同事們就從螞蟻巢穴中從基因方面篩選出了862種不同種類的真菌。這些真菌品種多樣——看來螞蟻在不斷培育新的真菌品種。讓人更加印象深刻的是，對真菌的DNA分析表明， 螞蟻通過頻繁地和周邊螞蟻羣體的交換和共享來改進或更新菌種。
史前人類沒有機會接觸城市化的生活方式——這一孕育智能的溫牀。而證據表明，螞蟻已經在城市環境中生存了將近一億年了，建造並維持着由特殊的洞穴和隧道構成的地下城市。
當我們考察墨西哥城、東京和洛杉磯時，都會驚歎人類的偉大成就。然而，Hoelldobler和Wilson在爲螞蟻愛好者創作的鉅著《螞蟻》中，描述了日本北海道石狩灣的石狩紅蟻所建造的超級蟻羣。據稱，在這個包含了4500個縱橫交錯的巣穴、幅員達2. 7平方公里的“巨大城市”中，生活着3. 6億隻工蟻和100萬隻蟻后。
如此堅固，複雜的網狀技術成就遠遠超越了我們的遠古祖先所取得的任何成就。人們在法國南部或者其他地方欣賞那些兩萬年前的巖畫傑作的時候對祖先的成就肅然起敬。而螞蟻的社會形態早在7000多萬年前就已經和現在相差無幾。此外，史前人類的技術看上去很原始。那麼，和當時的螞蟻社會相比，這還能算是另外一種形式的智能嗎?
在牛津大學、蘇賽克斯大學以及蘇黎世大學所作的研究表明，沙漠蟻在覓食歸巢途中，會結合它們腦中不斷更新的方向和距離資料來做導向。它們會將可見的地標與記憶庫中的區域方向結合來分門別類儲存，並不斷地使用和更新。因此螞蟻也具備學習能力。
在12年研究過程中，Ryabko和Reznikova找到了證據，證明螞蟻能夠傳遞非常複雜的信息。偵察蟻在迷宮中找到食物後返回去通知覓食隊伍。研究人員干涉了螞蟻交流的過程，在最後把偵察蟻弄走，看螞蟻團隊會有什麼反應。通常覓食隊伍會還是能夠繼續行進到迷宮中食物的確切位置。而在此之前，研究人員已經做了精密的預防措施，防止蟻羣通過氣味來傳遞信息。現在討論的焦點是，螞蟻在迷宮中行進路線的傳遞是通過一連串的左轉、右轉信息還是通過指南針式的方向和距離引導來完成的。
在這次全面的研究過程中，Reznikova全身心地投入到她實驗室的螞蟻身上，她感覺己認識每一隻螞蟻——即使它們身上沒有記號。無怪乎Edward Wilson在他的論文《與螞蟻相伴》中，建議那些詢問如何處理廚房中螞蟻的讀者：“注意腳下，珍惜小生命。”
TEST 3 PASSAGE 2 參考譯文：
人口遷移與遺傳學
A過去人們對人類起源與人口分佈的研究一直是在考古發現和化石證據的基礎上進行的。然而，從20世紀50年代起發明的不少新技術使得此項研究擁有更充分、更客觀的立足點。關於人口遷移活動的最早信息是從“活體考古”中獲得的，專家們可從遺傳物質中發現一些線索。
B 近來對人類何時初次踏上美洲大陸問題的研究便是體現這些新技術價股的最好範例。很久以來，東北亞和西伯利亞就一直被視爲人類首次向“北美新世界”遷移的發源地。但是，跨越白令海峽進人美洲大陸的移民浪潮是一次還是幾次?這次移民事件，或者這幾次事件又適何時發生的呢?近些年來，通過對遺傳學的研究，專家們找到遺傳標記在現代美國本土居民中分佈情況的新線索。
C 由生物人類學家羅伯特?威廉姆斯領導的一項程把研究點聚焦在了免疫球蛋白G變體(又叫做免疫球蛋白同種異型Gm)上。在人類血液流體中可以找到這種變體。所有的蛋質都處於漂流狀態，或者在生產新變體，那麼數代之後，通過通婚形成的家族成員們將會擁有一套共同的變體。所以，通過對比兩類不同人羣的Gm同種異型(比如兩個印第安人部落)人們可以建立各自的“遺傳距離”，距離本身可以調整，從而可以給出一些信息，提示此族羣自從最後一次通婚混血以來經過了多長吋間。
D威廉姆斯和他的同事們花費20年時間在北美西部地區採集了5, 000名美洲印第安人的血液標本。通過研究發現，這些印第安人的Gm同種異型可以劃分爲兩組，其中一組也和中部、南部的印第安人基因類型相匹配。其他測試顯示因紐特人(又叫愛斯基摩人)和阿留申人形成另一個族羣。據此證據可推斷出，跨越白令海峽的大規模移民浪潮共有三次。第一次移民浪潮發生在15,000年前，其中的古印第安人是今天美國中部和南部印第安人的祖先。約14, 000到12, 000年前的第二次移民浪潮帶來了納迪尼狩獵者，他們是納瓦喬人和阿帕切人(他們在約600或700年前從加拿大南部移民美國)的祖先。第三次浪潮發生在約10, 000或 9,000年前，從東北亞移民至北美大陸的這批人是現代愛斯基摩人和阿留申人的祖先。
E那麼，其他研究對此項結論的支持力度又有多大呢?遺傳學專家道格拉斯?華萊士通過研究三大彼此遠離的本土美洲人(亞利桑那州的皮馬-帕帕戈人、墨四哥尤卡坦半島的瑪雅印第安人、巴西亞馬遜河上游流域的迪古拿印第安人)血液樣本中的線粒體DNA發現：就像羅伯特?威廉姆斯的著作預測的那樣，三個族羣其實源於同一個祖先。
F此外，還有兩種研究進一步闡明瞭本土美洲人的起源問題它們涉及牙齒研究和語言研究。生物人類學家克里斯蒂?特納是一位從事人類牙齒生理特徵變化研究的專家。他認爲齒冠和齒根包含極高的遺傳因素，受環境和其他因素影響很小。根據對數千年來自新舊世界的樣本進行分析，特納發觀，大多數史前美洲人在齒冠和齒根特點上和亞洲北部人口有所聯繫，如鏟形門齒(牙齒單側或雙側邊緣嵴隆起而中部呈凹窩狀)，單重根上齒第一前磨牙和三重根下前第一磨牙。
據特納稱，這一特點和古印第安從北亞向外移民有所關聯，特納通過研究牙齒微進化速度得出這次移民發生在14，000年前。通過對牙齒的研究也發現了後面還有科納迪尼和愛斯基摩-阿留申這兩次移民浪潮。
自從20世紀50年代，語言學家約瑟夫?格林怕格就認爲，所有的本土美國語言同屬於唯一的一個印第安語系(除納迪尼和愛斯堪摩-阿留申以外)，此種觀點對三大主要移民浪潮的說法提供了憑證。格林伯格是同時代語言學家中的少數派，而大多數語言學家都贊成這樣一種觀點：一波又一波的移民浪潮解釋那一時期北美印第安人講1000多種語言的唯一依據。但是毫無疑問，新的遺傳學和牙齒證據爲格林伯格的觀點提供了強有力的支持。當然，關於移民的具體時間問題也要謹慎對待，除非這些信息有確鑿的考古證據的支撐。
TEST 3 PASSAGE 3 參考譯文：
歐洲森林保護計劃
森林是自然遺產的主要元素之一。過去15年歐洲森林的退化程度已經逐漸讓人們意識並瞭解到這種嚴重失調對他們的威脅。歐洲國家越來越重視歐洲森林受到的主要威脅，除了地理和氣候性的威脅以外，其他的都是不分國界的，諸如空氣污染、土壤退化、與日俱增的森林火災，有時候甚至是我們對林地和森林的管理不善。人們也越來越清楚地認識到各國需要聯合起來協調政策。1990年12月，在法國斯特拉斯堡舉行了第一次以保護歐洲森林爲主題的部長級會議，來自東西歐的31國家代表彙集一堂。會議的議題包括： 如何協調研究對森林的破壞，如何防範森林火災，以及歐洲森林生態系統研究項目的擴大。會議舉行前召開了兩次專家會議來做會前準備工作。他們最初的任務是決定在歐洲森林所面臨的諸多問題中，哪個問題所涉及的國家最多，可作爲各國聯合行動的主題。因此那些受特殊地理條件限制的地區，如地中海以及北歐國家就被排除在外了。但是以後他們還是有可能參與進來的。
總體而言，歐洲國家認爲森林有三重功能——生物、經濟和娛樂功能。第一重是扮演地球的“綠色之肺”;通過光合作用，森林在太陽能量轉換過程中釋放。對人類而言，它是不可替代的巨大而無污染的能量來源。同時，通過不斷再生的木材，森林還爲人類活動提供了原材料。最後，森林還爲那些在城市裏每週五天深陷於工作的上班族們提供了無與倫比的自由氛圍去釋放心情，參與遊獵、騎馬以及遠足等休閒活動。森林的經濟功能從人類起源開始就被發現了——木材就是最初的燃料。其他功能的發現僅有幾個世紀的歷史，但它們變得越來越重要。因此，整個歐洲十分關注威脅到森林使其不能扮演這三重基本功能的破壞性行爲。
有關天然森林的古老神話還在歐洲大陸流傳着，而事實上，真正的原始森林已經不復存在了。所有的歐洲森林都是人工種植的，被人類改造和開發了數千年。這就意味着，一項超越國界、跨越年代的森林政策至關重要，並且必須要考慮到森林環境、人民需求，國家政策發生不可避免的變化。斯特拉斯保會議是同等規模的活動中最先達成該結論的活動之一。其總宣言爲：任何具有生態延續性的森林政策的核心內容，都必須着眼於長期的可持續性以及不可預見的狀況可能帶來的影響，以保證森林的全部潛能都可以得到維繫。
除了總宣言，會議還提出了六項有利於國家政策制定的詳細決議。第一項決議是對森林退化監測站進行擴建並使其系統化。我們對森林退化的瞭解還不多，但它會造成樹葉和針葉的大量脫落。整個歐洲大陸以及大多數樹種都受到影響，受影響樹木佔樹木總量的30%到50%這樣的情況像是由一系列因素累積導致的，大氣污染就是其中的罪魁禍首。還需要特別注意氮化物和二氧化硫。然而，一些氣候因素如干旱、寒冬，以及破壞樹木根系的土壤酸化等土地失衡狀況，可能會加劇這些不利因素的影響。第二項決議的重點是保持歐洲森林基因多樣性的需求。目標是改變樹種減少的狀況或者至少保留所有樹種的基因資料。雖然森林大火對歐洲各國的影響程度不同，但是其破壞力卻讓專家們提出第三個決議：斯特拉斯堡會議應該考慮就此主題建立一個歐洲數據庫。所有國家保護政策發展過程中所用的信息將被廣泛分享。部長們所討論的第四項決議是關於山林的。在歐洲變化最快、處境最危險的無疑是山地生態系統，常住人口的零星分佈以及休閒活動特別是滑雪，給當地生態系統造成了嚴重而長期的改變。建議的改進措施包括優先建立一項關於山林的研究項目。第五項決議重新發布了有關樹木生理學的名爲“森林持續發展”的歐洲研究網“森林持續發展”將支持歐洲各國聯合研究樹木的病害以及生理和生化方面的問題。每個參與國都可以增加獎學金以及其他經濟支持來鼓勵此領域博士論文的撰寫以及研究項目的開展。會議最終建立了歐洲森林生態系統的科研網絡，用以協調各國行動以及確認一些和森林保護相關的重點研究議題，斯特拉斯堡會議的重點是着眼於未來。這一最初的動機現在已成爲31名參加者代表的31個歐洲國家的共同動力。他們最後的承諾是肩負起對森林的責任，保證政府代表間相關的討論交流。
劍橋雅思閱讀7原文解析(test3)
Test 3 Passage 1
Question 1
答案：FALSE
關鍵詞：channels, communication, humans
定位原文: 第2段第2、3句: “Such chemical communication can be… Ants are so much like …”
解題思路: 此題可以通過定位詞迅速定位第2段的這兩句話。兩句話中都只是說明螞蟻的生物行爲與人類非常相似，而題目中則說是“相同”，與原文相悖，因此答案很明顯應該是 FALSE 。
Question 2
答案：TRUE
關鍵詞：city life, intelligence
定位原文: 第7段第1句: “Whereas prehistoric man had …” 此題的定位比較有難度，定位詞並未以原形出現。但若根據順序原則由第3題的定位段落(第8段)向前查找會比較容易。
解題思路: 文章與題目出現同義轉換：urban life — city life; forcing house — encourages
該題的解題關鍵在於是否能正確理解文中短語forcing house的含義，它的含義爲“溫牀”， 與題中解題關鍵字：encourages完全吻合。因此此題答案爲TRUE。
Question 3
答案： NOT GIVEN
關鍵詞：build large cities
定位原文: 第8段第1句: “’re amazed at what has been accomplished by humans.”
第9段第1句: “Such enduring and intricately meshed levels…”
解題思路: 文章第8段提到了人類建造城市的例子，第9段指出螞蟻的技術遠遠超過我們的祖先，但是文章並未提到螞蟻和人類的建造速度，也未對此作任何的比較。此題屬於典型的文章未提及型題目，因此應該選擇NOT GIVEN。
Question 4
答案：TRUE
關鍵詞：distance and position
定位原文: 第10段第1句: “ navigate by integrating bearings and distances...”它們通過整合方向和距離來導航。
解題思路: 此題通過定位詞可以迅速定位到第10段該句，且該句含義與題目一致。 文章與題目出現同義轉換：find their way — navigate; making calculations — integrating; bearings — position. 因此此題答案爲TRUE。
Question 5
答案：FALSE
關鍵詞：foraging teams
定位原文: 第11段倒數第2句: “Elaborate precautions were…”
解題思路: 此題利用定位詞很容易定位，且文中定位處出現g odour clues，其含義爲防止使用氣味線索，而題幹中的解題要點爲螞蟻使用嗅覺尋找食物。很明顯，此題題干與原文內容相悖，因此答案爲FALSE。
Question 6
答案：NOT GIVEN
關鍵詞： “In the company of ants”
定位原文: 末段最後1句：“ his essay, ‘In the company of ants’, advises …”
解題思路: 此題定位非常容易。在定位句中，作者僅僅強調了需要將螞蟻視爲有智能的生命來對待，對於題幹中的解題點“螞蟻的信息交流”是否進行研究並未提及。此題屬於典型的“題幹信息文章部分提及”，因此此題答案爲NOT GIVEN。
Question 7
答案： C
關鍵詞：cultivate, they can digest
定位原文: 第5段第2、3句：“Ants can’t digest… The ants therefore…”
解題思路:此題通過在定位段落第5段中掃描定位詞，可以將其定位在第2、3句，其含義爲“螞蟻不能消化葉子中的纖維素，但是一些真菌可以。因此螞蟻在自己的巢中培養這些真菌”。題幹中此題應填一個名詞，且根據其後信息判斷出該名詞在經過轉變後能被螞蟻消化，於是可以直接選出答案C。
Question 8
答案： M
關鍵詞：weed-killers
定位原文: 第5段最後1句: “Farmer ants secrete antibiotics…”
解題思路: 按照順序原則在第7題後掃描定位詞可以迅速定位。通過閱讀此空之後的題幹信息可推出所填單詞應爲名詞，且其行爲爲kill weeds;通過掃描定位句，其中滿足條件的詞爲antibiotics，但在詞庫中並未出現，此時只能選出其上下義詞，即爲選項M。
Question 9
答案：F
關鍵詞： unwanted materials
定位原文: 第5段最後1句: “ spread waste to fertilise the crop.”
解題思路: 此題在文中定位緊接着上一題。通過題幹中空格之前的信息可以判斷出所填詞爲複數名詞，且其等價於unwanted materials。在文中定位處找到其對應詞waste,且其作用爲fertilise the crop;在題目所給詞庫中的複數名詞裏進行快速掃描，答案只能爲F。
Question 10
答案：D
關鍵詞：new species, neighbouring ant colonies
定位原文: 第6段最後1句: “…the ants improve or modify …”
解題思路: 通過分析空格判斷出所填詞應爲v+ing形式(and前後結構相同)，在文中定位句中對應詞爲swapping and sharing (交換和分享);在題目所給詞庫中滿足v+ing形式的詞裏進行快速掃描，答案只能爲D。
Question 11
答案：N
關鍵詞：agribusiness, methods
定位原文: 第4段第2、3句：“The farming methods ... They do not ruin…”
解題思路: 此題出現了亂序，但是通過掃描定位詞還是可以迅速在文中找到對應詞。首先是出現在第3段最後1句話中的agribusiness，接下來纔是第4段第2句中的farming methods。通過分析題幹中空格前後的信息，判定所填單同應爲形容詞，且其修飾對象爲methods;在文中定位處的對應詞爲 sustainable，對應答案N。
Question 12
答案： O
關鍵詞：affect
定位原文: 第4段第2、3句: “The farming methods... They do not ruin…”
解題思路:由於空格之前爲動詞，所以應回原文找尋該動詞或其同義詞;在文中定位處對應詞爲ruin, 所以答案爲其後單詞environment，即O選項
Question 13
答案： E
關鍵詞：waste
定位原文: 第4段第2、3句: “The farming methods ... They do not ruin…”
解題思路: 文中定位處對應詞爲use enormous amounts of，所以答案爲其後單詞energy，即E選項。
Test 3 Passage 2
Question 14
答案：iv
關鍵詞：developments
定位原文: A段第2句: “A number of techniques…”
解題思路: A段中間部分出現轉折句，主要含義爲一系列的新技術使得該研究變得更加良性和客觀。在段義選項中只有iv選項中的關鍵詞developments能與之匹配，因此答案爲iv。
Question 15
答案：vii
關鍵詞：problem
定位原文: B段首句: “Recent work on the problem…”
解題思路: B段首句引出了首次進入美洲大陸人口的問題，在段義選項中只有vii和ix滿足條件，但是B段並未提到人類遷移的原因，而只是在段落後半部分提出了一系列的問題，所以ix不對，答案應該爲vii。
Question 16
答案：x
關鍵詞：two different populations; establish their genetic “distance”
定位原文: C段末句: “Thus, by comparing…”
解題思路: C段中提出了一種研究方法，即研究variants，並在最後由thus引出了結論，通過比較兩類不同人羣就能建立他們之間的“遺傳距離”。在段義選項中只有最後一個滿足要求，其中對應關鍵詞爲 blood-variants, closeness, between different populations，因此答案爲x。
Question 17
答案：i
關鍵詞：found that
定位原文: D段第2句: “They found that…”
解題思路: 此段大意其實可以按照邏輯發展順序迅速地確定爲i，這是因爲上一段介紹了一個研究，此段應該介紹研究結果，而段義選項中只有i爲研究結果。或者通過通讀全段，得出主題句爲：他們發現這些Gm可以分爲兩大類。這就是研究的結論，從其後文字均爲介紹性文字，也可以判定此段段義爲選項i。
Question 18
答案：vi
關鍵詞：other research
定位原文: E段首句: “How far does other research support these conclusions?”
解題思路: E段首句即提出了其他研究是否能支持上一段結論的問題，然後列舉出了其他實驗的例子。在段義選項中，只有vi選項中提到了其他研究(further genetic evidence),故答案是vi。
Question 19
答案：ii
關鍵詞：dental
定位原文: F段第2句：“The biological anthropologist Christy Turner is…”
解題思路: 此段首句極具迷惑性，其含義爲另兩種關於牙齒和語言的研究也能解釋這個問題，所以可能錯選 iii，因爲其中包含關鍵詞dental and linguistic evidence，但是iii中人物Greenberg僅出現在下一段，故排除此選項。此段真正主題句爲第二句，此句介紹了研究牙齒也能解釋問題，其後文字全部爲介紹牙齒研究的文字，故答案爲ii。
Question 20
答案：E
關鍵詞：15, 000 or more
定位原文: D段中部倒數第4句： “e major waves of migration…”
解題思路: 定位處說明了此處的wave應該across the Bering Strait，所以答案應該在B、C、E中篩選，在圖中可以很明顯地定位出原文相關詞Central American和 South American，故答案爲其對應選項E。
Question 21
答案：D
關鍵詞： 600 to 700
定位原文: D段後半部倒數第2句: “... and Apache (who only migrated south from Canada about 600 or 700 years ago).”
解題思路: 定位處的說明爲：僅僅在600或700年前從加拿大向南部遷移。
在圖中各條箭頭中只有D的起點在Canada，且箭頭方向向南，故答案爲D。
Question 22
答案：C
關鍵詞： Inuit
定位原文: D段第3句: “Other tests showed…”
解題思路:
由此句可以很明顯地判斷出Inuit屬於第三類，因此答案爲C。
Question 23
答案：B
關鍵詞： Apache
定位原文: D段倒數第2句: “The second wave…”
解題思路:
由此句可以很明顯地判斷出Apache屬於第二類，因此答案爲B。
Question 24
答案：A
關鍵詞：Pima-Papago
定位原文: E段第二句: “d samples from three widely separated Native American
…” E段最後一句: “… all three groups appear to be descended…”
解題思路: 通過定位句可判定Pima-Papago屬於 “three groups”中的一種，且均來自於 Paleo-lndian; Paleo-lndian在D段倒數第三句出現過：The first，Paleo-lndian，wave...故答案爲A
Question 25
答案： A
關鍵詞：Ticuna
定位原文: E段倒數第2句: “… and Ticuna Indians in the Upper Amazon region of Brazil…” D段倒數第三句: “The first, Paleo-lndian, wave … was ancestral to all Central and South American Indians”.
解題思路:定位這兩句，可以發現Ticuna Indians也屬於first wave
Question 26
答案： A
關鍵詞：Christy Turner
定位原文: 通過題幹粗定位於文章F段第2句: “Christy Turner is an expert …” F段最後一句: “Studies carried out by…”
解題思路: 通過F段第2句可知：特納的研究主要是分析人類牙齒的生理特徵，因此可以排除未提及牙齒的選項 B和D。C選項極具迷惑性，其中“the majority of prehistoric Americans”與全文一致，但是這一內容只是實驗結果所“suggest”的，而並非特納真正的實驗內容;A選項與原文 “ many thousands of New and Old World specimens，both ancient and modem”含義完全一致。故正確答案爲A。
Test 3 Passage 3
Question 27
答案：NOT GIVEN
關鍵詞： Mediterranean countries
定位原文: 第1段末最後兩句: “…such as counties bordering Mediterranean … However, this dose not mean…”
解題思路: 此題通過定位詞可以迅速定位到第一段最後兩句話，其含義爲地中海國家在日後不一定被忽略;而題幹則爲在下次會議中會討論，顯然爲文中未提及內容。故此題答案爲NOT GIVEN。
Question 28
答案：FALSE
關鍵詞：Nordic countries
定位原文: 第1段末倒數第3句和倒數第2句：“Their initial task was to… Those confined to particular geographical areas…”
解題思路: 該題考查因果關係，由定位句中的因果關係詞therefore推出解題句爲定位句的前一句：Nordic countries不被考慮是因爲會議要決定哪些森林問題涉及的國家最多並且能夠成爲聯合行動的主題，這與題幹中的原因不同，而考查因果關係時要求文章與題目精確，故此題答案爲FALSE。
Question 29
答案：TRUE
關鍵詞： raw material
定位原文: 第2段第3句: “forests provide raw materials…”
解題思路: 此題的定位詞在文中以原詞出現，按照順序原則可以迅速定位。文中定位處含義爲：通過其不斷再生的木材，森林給人類活動提供了原材料。文章與題目含義一致。故此題答案爲TRUE。
Question 30
答案：FALSE
關鍵詞：biological functions, recognised
定位原文: 第2段倒數第3句、倒數第2句: “The economic importance of forests has been... The other aspects have been…”
解題思路: 此題先通過biological functions定位於第二段首句，其中提到森林的三種功能爲 biological，economic和recreational;然後由recognised精確定位到解題句，其中提到除了economic之外的兩方面都已經被認可了幾個世紀，而題目卻認爲其僅僅是在20世紀才被認可的。題目明顯與文章相悖，故此題答案爲FALSE。
Question 31
答案：FALSE
關鍵詞：natural forests
定位原文: 第3段第2句: “All European forests are artificial”
解題思路: 此題通過定位詞可定位於第3段首句，通過掃讀得出解題句，其含義爲：歐洲所有的森林都是人工種植的，很顯然題目與文章內容剛好相反，故此題答案爲FALSE。
Question 32
答案：FALSE
關鍵詞：forest policy, national boundaries
定位原文: 第3段第3句: “This means that…”
解題思路: 此題通過定位詞能夠迅速定位。定位句的含義爲：森林政策至關重要，它必須超越國家的界限。顯然題目與文章內容相反，故此題答案爲FALSE。
Question 33
答案：TRUE
關鍵詞： Strasbourg conference, forest policy, change
定位原文: 第3段第3句、第4句：“This means that a forest policy… The Strasbourg conference was…”這就意味着一項森林政策至關重要，它必須考慮到森林環境，人民需求，國家政策發生不可避免的變化。斯特拉斯堡會議也成爲此類髙規格創始會議中達成該結論的會議之一。
解題思路: 此題通過定位詞能夠迅速定位。定位句指出會議達成this conclusion，此處出現指代，按“遇指代，向前看一句”的原則得到定位句首句。定位句中結論與題目含義一致，故此題答案爲 TRUE。
Question 34
答案：J
關鍵詞：resolution 1
定位原文: 第4段第2句: “The first proposes the extension…” 第一項決議是對森林退化監測站進行擴建並使其系統化。
解題思路: 在選項中掃描關鍵詞，只有J選項符合該含義：森林的任何退化信息都將被系統地收集。此處有兩個干擾選項，F和I。F選項中出現文中原詞monitored，但對loss of leaves的監測只是決議I中的一項內容，不全面。 I選項中出現文中原詞 soil imbalance, acidification, compounds of nitrogen and sulphur，但這些詞在文中分別出現於不同的例子中，而I選項卻將其揉在一句話中。 故答案爲J。
Question 35
答案： A
關鍵詞：resolution 2
定位原文: 第4段中部第8句: “The second resolution concentrates on…”第二項決議的重點是保持歐洲森林站基因多樣性的需求。
解題思路: 在選項中掃描關鍵詞，只有A選項出現關鍵詞preserve, 且其含義與原文相符：所有種類的樹木都必須被保存。故答案爲A。
Question 36
答案： E
關鍵詞：resolution 3
定位原文: 第4段第10句：“Although forest fires do not...” 雖然森林大火對歐洲各國的影響程度不同，但是其破壞力卻讓專家們提出第三個決議：斯特拉斯堡會議應該考慮就此主題建立一個歐洲數據庫
解題思路: 在選項中掃描關鍵詞，只有E選項出現關鍵詞forest fires，且其含義與原文相符：有關森林大火的信息需被收集並分享。故答案爲E。
Question 37
答案： B
關鍵詞：resolution 4
定位原文: ：第4段倒數第9句: “Proposed developments include…” 建議的改進措施包括優先建立一項關於山林的研究項目。
解題思路: 在選項中掃描關鍵詞，只有B選項出現關鍵詞mountain forests和priority (對應 preferential), 且其含義與原文相符：脆弱的山林應該在研究項目中優先考慮, 故答案爲B。
Question 38
答案：G
關鍵詞：resolution 5
定位原文: 第4段倒數第8句、倒數第7句：“Eurosilva should support... Each country concerned could…”“森林持續發展”將支持歐洲各國聯合研究樹木的病害以及生理和生化方面的問題。每個參與國都可以增加獎學金以及其他經濟支持來鼓勵此領域博士論文的撰寫以及研究項目開展。
解題思路: 在選項中掃描關鍵詞，只有G選項出現關鍵詞allocated to research和tree diseases, 且其含義與原文相符：資源必須分配給關於樹木病害的研究。
故答案爲G。
Question 39
答案： D
關鍵詞：resolution 6
定位原文: 第4段倒數第5句：“Finally, the conference established…”會議最終建立了歐洲森林生態系統的科研網絡
解題思路: 在選項目掃描關鍵詞，只有D選項出現關鍵詞co-ordinated(對應research network), 且其含義與原文相符：研究最好在整個歐洲範圍內進行，以便更好地相互協作。故答案爲D。
Question 40
答案： B
關鍵詞： 無
定位原文: 全文結構
解題思路: 通過分析文中首句可以得出，其中關鍵詞爲forests，從而排除不含此關鍵詞的選項C; A選項中的三個關鍵詞biological, economic和recreational均未在末句中提及，故排除;B和D兩個選項中關鍵詞分別爲：B強調protect，D強調policy on management。文章末句中government以及responsibility for forests強調政府對於森林的責任而並非管理，排除D選項。故正確答案爲B。
