1、雅思（阅读）模拟试卷 92及答案与解析 0 You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below. The construction of roads and bridgesRoadsAlthough there were highway links in Mesopotamia from as early as 3500 BC, the Romans were probably the first road-builders with fixed engi
2、neering standards. At the peak of the Roman Empire in the first century ad, Rome had road connections totalling about 85,000 kilometres.Roman roads were constructed with a deep stone surface for stability and load-bearing. They had straight alignments and therefore were often hilly. The Roman roads
3、remained the main arteries of European transport for many centuries, and even today many roads follow the Roman routes. New roads were generally of inferior quality, and the achievements of Roman builders were largely unsurpassed until the resurgence of road-building in the eighteenth century.With h
4、orse-drawn coaches in mind, eighteenth-century engineers preferred to curve their roads to avoid hills. The road surface was regarded as merely a face to absorb wear, the load-bearing strength being obtained from a properly prepared and well-drained foundation. Immediately above this, the Scottish e
5、ngineer John McAdam(1756-1836)typically laid crushed stone, to which stone dust mixed with water was added, and which was compacted to a thickness of just five centimetres, and then rolled. McAdams surface layer hot tar onto which a layer of stone chips was laidbecame known as tarmacadam, or tarmac.
6、 Roads of this kind were known as flexible pavements.By the early nineteenth century the start of the railway age men such as John McAdam and Thomas Telford had created a British road network totalling some 200,000 kilometres, of which about one sixth was privately owned toll roads called turnpikes.
7、 In the first half of the nineteenth century, many roads in the US were built to the new standards, of which the National Pike from West Virginia to Illinois was perhaps the most notable.In the twentieth century, the ever-increasing use of motor vehicles threatened to break up roads built to ninetee
8、nth-century standards, so new techniques had to be developed.On routes with heavy traffic, flexible pavements were replaced by rigid pavements, in which the top layer was concrete, 15 to 30 centimetres thick, laid on a prepared bed. Nowadays steel bars are laid within the concrete. This not only res
9、trains shrinkage during setting, but also reduces expansion in warm weather. As a result, it is possible to lay long slabs without danger of cracking.The demands of heavy traffic led to the concept of high-speed, long-distance roads, with access or slip-lanes spaced widely apart. The US Bronx River
10、Parkway of 1925 was followed by several variantsGermanys autobahns and the Pan American Highway. Such roads especially the intercity autobahns with their separate multi-lane carriageways for each direction were the predecessors of todays motorways.BridgesThe development by the Romans of the arched b
11、ridge marked the beginning of scientific bridge-building; hitherto, bridges had generally been crossings in the form of felled trees or flat stone blocks. Absorbing the load by compression, arched bridges are very strong. Most were built of stone, but brick and timber were also used. A fine early ex
12、ample is at Alcantara in Spain, built of granite by the Romans in AD 105 to span the River Tagus. In modern times, metal and concrete arched bridges have been constructed. The first significant metal bridge, built of cast iron in 1779, still stands at Ironbridge in England.Steel, with its superior s
13、trength-to-weight ratio, soon replaced iron in metal bridge-work. In the railway age, the truss(or girder)bridge became popular. Built of wood or metal, the truss beam consists of upper and lower horizontal booms joined by vertical or inclined members.The suspension bridge has a deck supported by su
14、spenders that drop from one or more overhead cables. It requires strong anchorage at each end to resist the inward tension of the cables, and the deck is strengthened to control distortion by moving loads or high winds. Such bridges are nevertheless light, and therefore the most suitable for very lo
15、ng spans. The Clifton Suspension Bridge in the UK, designed by Isambard Kingdom Brunei(1806-1859)to span the Avon Gorge in England, is famous both for its beautiful setting and for its elegant design. The 1998 Akashi Kaikyo Bridge in Japan has a span of 1,991 metres, which is the longest to date.Can
16、tilever bridges, such as the 1889 Forth Rail Bridge in Scotland, exploit the potential of steel construction to produce a wide clearwater space. The spans have a central supporting pier and meet midstream. The downward thrust, where the spans meet, is countered by firm anchorage of the spans at thei
17、r other ends. Although the suspension bridge can span a wider gap, the cantilever is relatively stable, and this was important for nineteenth-century railway builders. The worlds longest cantilever span 549 metresis that of the Quebec rail bridge in Canada, constructed in 1918.Questions 1-3Label the
18、 diagram below.Choose NO MORE THAN TWO WORDS AND/OR A NUMBER from the passage for each answer.3 Do the following statements agree with the information given in Reading Passage 1 ? Write TRUE if the statement agrees with the information FALSE if the statement contradicts the information NOT GIVEN if
19、there is no information on this 4 Road construction improved continuously between the first and eighteenth centuries. 5 In Britain, during the nineteenth century, only the very rich could afford to use toll roads. 6 The Nineteenth-century road surfaces were inadequate for heavy motor traffic. 7 Traf
20、fic speeds on long-distance highways were unregulated in the early part of the twentieth century. 7 Complete the table below.Use ONE WORD ONLY from the passage for each answer.13 You should spend about 20 minutes on Questions 14-26, which are based on Reading Passage 2 below. Neanderthals and modern
21、 humans A The evolutionary processes that have made modern humans so different from other animals are hard to determine without an ability to examine human species that have not achieved similar things. However, in a scientific masterpiece, Svante Paabo and his colleagues from the Max Planck Institu
22、te for Evolutionary Anthropology, in Leipzig, have made such a comparison possible. In 2009, at a meeting of the American Association for the Advancement of Science, they made public an analysis of the genome* of Neanderthal man. B Homo neanderthalensis, to give its proper name, lived in Europe and
23、parts of Asia from 400,000 years ago to 30,000 years ago. Towards the end of this period it shared its range with interlopers in the form of Homo sapiens*, who were spreading out from Africa. However, the two species did not settle down to a stable cohabitation. For reasons which are as yet unknown,
24、 the arrival of Homo sapiens in a region was always quickly followed by the disappearance of Neanderthals. C Before 2009, Dr Paabo and his team had conducted only a superficial comparison between the DNA of Neanderthals and modern humans. Since then, they have performed a more thorough study and, in
25、 doing so, have shed a fascinating light on the intertwined history of the two species. That history turns out to be more intertwined than many had previously believed. D Dr Paabo and his colleagues compared their Neanderthal genome(painstakingly reconstructed from three bone samples collected from
26、a cave in Croatia)with that of five living humans from various parts of Africa and Eurasia. Previous genetic analysis, which had only examined DNA passed from mother to child in cellular structures called mitochondria, had suggested no interbreeding between Neanderthals and modern humans. The new, m
27、ore extensive examination, which looks at DNA in the cell nucleus rather than in the mitochondria, shows this conclusion is wrong. By comparing the DNA in the cell nucleus of Africans(whose ancestors could not have crossbred with Neanderthals, since they did not overlap with them)and various Eurasia
28、ns(whose ancestors could have crossbred with Neanderthals), Dr Paabo has shown that Eurasians are between one percent and four percent Neanderthal. E That is intriguing. It shows that even after several hundred thousand years of separation, the two species were inter-fertile. It is strange, though,
29、that no Neanderthal mitochondrial DNA has turned up in modern humans, since the usual pattern of invasion in historical times was for the invaders males to mate with the invadeds females. One piece of self-knowledge, then at least for non-Africans is that they have a dash of Neanderthal in them. But
30、 Dr Paabos work also illuminates the differences between the species. By comparing modern humans, Neanderthals, and chimpanzees, it is possible to distinguish genetic changes which are shared by several species of human in their evolution away from the great-ape lineage, from those which are unique
31、to Homo sapiens. F More than 90 percent of the human accelerated regions* that have been identified in modern people are found in Neanderthals too. However, the rest are not. Dr Paabo has identified 212 parts of the genome that seem to have undergone significant evolution since the species split. Th
32、e state of genome science is still quite primitive, and it is often unclear what any given bit of DNA is actually doing. But an examination of the 20 largest regions of DNA that have evolved in this way shows that they include several genes which are associated with cognitive ability, and whose malf
33、unction causes serious mental problems. These genes therefore look like good places to start the search for modern humanitys essence. G The newly evolved regions of DNA also include a gene called RUNX2, which controls bone growth. That may account for differences in the shape of the skull and the ri
34、b cage between the two species. By contrast an earlier phase of the study had already shown that Neanderthals and moderns share the same version of a gene called FOXP2, which is involved in the ability to speak, and which differs in chimpanzees. It is all, then, very promising and a second coup in q
35、uick succession for Dr Paabo. Another of his teams has revealed the existence of a hitherto unsuspected species of human, using mitochondrial DNA found in a little-finger bone. If that species, too, could have its full genome read, humanitys ability to know itself would be enhanced even further. * a
36、n individuals complete set of genes * the scientific name for modern humans * parts of the human brain which evolved very rapidly Questions 14-18 Look at the following characteristics(Questions 14-18)and the list of species below. Match each feature with the correct species, A, B or C. Write the cor
37、rect letter, A, B or C. NB You may use any letter more than once. List of species A Homo neanderthalensis B Homo sapiens C both Homo neanderthalensis and Homo sapiens 14 Once lived in Europe and Asia. 15 Originated in Africa. 16 Did not survive long after the arrival of immigrants. 17 Interbred with
38、 another species. 18 Appears not to have passed on mitochondrial DNAto another species. 18 Reading Passage 2 has seven paragraphs, A-G. Which paragraph contains the following information? Write the correct letter, A-G. 19 an account of the rejection of a theory 20 reference to an unexplained link be
39、tween two events 21 the identification of a skill-related gene common to both Neanderthals and modern humans 22 the announcement of a scientific breakthrough 23 an interesting gap in existing knowledge 23 Complete the summary below. Choose NO MORE THAN THREE WORDS from the passage for each answe, Th
40、e nature of modern humans Recent work in the field of evolutionary anthropology has made it possible to compare modern humans with other related species. Genetic analysis resulted in several new findings. First, despite the length of time for which Homo sapiens and Homo neanderthalensis had develope
41、d separately, 【 R24】 _did take place. Secondly, genes which evolved after modern humans split from Neanderthals are connected with cognitive ability and skeletal 【 R25】 _. The potential for this line of research to shed light on the nature of modern humans was further strengthened when analysis of a
42、 【 R26】 _led to the discovery of a new human species. 24 【 R24】 25 【 R25】 26 【 R26】 26 You should spend about 20 minutes on Questions 27-40, which are based on Reading Passage 3 below. The future of fish The face of the ocean has changed completely since the first commercial fishers cast their nets
43、and hooks over a thousand years ago. Fisheries intensified over the centuries, but even by the nineteenth century it was still felt, justifiably, that the plentiful resources of the sea were for the most part beyond the reach of fishing, and so there was little need to restrict fishing or create pro
44、tected areas. The twentieth century heralded an escalation in fishing intensity that is unprecedented in the history of the oceans, and modern fishing technologies leave fish no place to hide. Today, the only refuges from fishing are those we deliberately create. Unhappily, the sea trails far behind
45、 the land in terms of the area and the quality of protection given. For centuries, as fishing and commerce have expanded, we have held onto the notion that the sea is different from the land. We still view it as a place where people and nations should be free to come and go at will, as well as somew
46、here that should be free for us to exploit. Perhaps this is why we have been so reluctant to protect the sea. On land, protected areas have proliferated as human populations have grown. Here, compared to the sea, we have made greater headway in our struggle to maintain the richness and variety of wi
47、ldlife and landscape. Twelve percent of the worlds land is now contained in protected areas, whereas the corresponding figure for the sea is but three-fifths of one percent. Worse still, most marine protected areas allow some fishing to continue. Areas off-limits to all exploitation cover something
48、like one five-thousandth of the total area of the worlds seas. Today, we are belatedly coming to realise that natural refuges from fishing have played a critical role in sustaining fisheries, and maintaining healthy and diverse marine ecosystems. This does not mean that marine reserves can rebuild f
49、isheries on their ownother management measures are also required for that. However, places that are off-limits to fishing constitute the last and most important part of our package of reform for fisheries management. They underpin and enhance all our other efforts. There are limits to protection though. Reserves cannot bring back what has died out. We can never resurrect globally extinct species, and restoring locally extinct animals may require reintroductions from elsewhere, if natural dispersal from remaining populations is insufficient
