1、大学英语六级改革适用（阅读）模拟试卷 49及答案与解析 Section C 0 Two new studies offer signs that this could be changing quickly. One offers a new way to produce solar cells more cheaply and safely than current methods. The other indicates that concentrating solar power, which uses the sun s energy to heat up a liquid that
2、drives a turbine, could supply “a substantial amount of current energy demand.“ In a study released Wednesday in journal Nature, University of Liverpools Jon Major and several other researchers announced that they had found that magnesium chloride, which is used in making tofu, bath salts and applie
3、d to roads in the winter could replace cadmium chloride in the making of second-generation, thin-film solar cells. Speaking in a teleconference from Copenhagen, Major said magnesium chloride, which is extracted from seawater, would cost $0,001 per gram compared to $0.3 for cadmium chloride. It would
4、 also eliminate the challenges and expense of handling cadmium chloride, a highly toxic compound that requires elaborate safety measures to protect workers during its manufacture and a special disposal process when panels are no longer needed. “So what we have done without any loss of efficiency is
5、to replace expensive and highly toxic material with one that is completely benign and much lower in cost in the process,“ Major said. “This offers a great cost benefit for production of these kinds of solar cells and could help make a step change in the production of them.“ The solar market is curre
6、ntly dominated by panels made with silicon. In a bid to make solar more competitive, there is growing interest from companies like First Solar in developing solar cells using cadmium telluride, which is more efficient and more flexible so it could be applied many more surfaces including windows. To
7、make these cadmium telluride cells, a thin layer of cadmium chloride is applied to the solar cell, and then heated up in a furnace. This is considered the activation process, Major said, helping to boost a cells efficiency from around 1 percent to as much as 20 percent. In a bid to find a safer alte
8、rnative, Major and his team first looked at sodium chloride, but found the efficiency was about half of cadmium chloride. Another option was difluoro chloromethane but that has been linked to ozone depletion and its use has been restricted by international agreements. They then turned to magnesium c
9、hloride and found that it was just as efficient as comparable and could be applied without any expensive safety equipment. Major said magnesium chloride isnt being used at the moment, but was hopeful it “would be taken up by research and hopefully by industry once this work is publicized.“ Steve Kru
10、m, the director of corporate communications for First Solar, would only say cadmium chloride remains “critical part“ of its production process and that it was not a “major cost driver in our manufacturing process.“ 1 What does “a new way to produce solar cells more cheaply and safely than current me
11、thods“ in the first paragraph refer to? （ A） Using cadmium chloride as material to produce solar cells. （ B） Using magnesium chloride as material to produce solar cells. （ C） Using sodium chloride as material to produce solar cells. （ D） Using difluoro chloromethane as material to produce solar cell
12、s. 2 Which of the following is not the reason why cadmium chloride is replaced by magnesium chloride? （ A） Magnesium chloride is cheaper than cadmium chloride. （ B） Magnesium chloride has no poison. （ C） The efficiency of magnesium chloride is as high as cadmium chloride. （ D） Magnesium chloride can
13、 produce more efficiency than cadmium chloride. 3 The word “benign“(Line 2, Para. 4)may be replaced by_. （ A） sweet （ B） humane （ C） nontoxic （ D） amiable 4 Why do many companies become more interested in developing solar cells using cadmium telluride? （ A） Because cadmium telluride is more efficien
14、t and more flexible. （ B） Because cadmium chloride is needed in the process. （ C） Because it is much safer than magnesium chloride. （ D） Because it can complete the developing process independently. 5 The best title of the passage may be_. （ A） How to Make Solar Cells （ B） The Future of Solar Power
15、（ C） Magnesium Chloride is to Make Solar Cells （ D） Magnesium Chloride Replaced Cadmium Chloride 5 It may seem ridiculous, but in the hunt for sources of alternative energy researchers have come up with fuel cells which are powered by cheese or at least whey, a by-product in cheese making. Whey is r
16、ich in lactose, a sugar which Georgia Antonopoulou, a biochemical engineer at the University of Patras, Greece, says can be consumed by cultures of bacteria contained within a fuel cell to generate an electric current. Microbial fuel cells, as such devices are known, are not a new idea but they are
17、attracting more attention. The organic contents of whey pose an environmental hazard and many governments now impose strict regulations requiring factories to pay for its treatment before disposal. Whey constitutes about 70% of the volume of the milk were used to make cheese. So, just one small feta
18、 facility will need to dispose of as such as 4,000 tonnes of whey in a single year, says Dr Antonopoulou. Microbial fuel cells could help, and not just in the cheese-making industry. Breweries, pig farms, food-processing plants and even sewage works could gain from the technology. Traditional fuel c
19、ells work by using a catalytic material to oxidize a fuel, such as hydrogen, and make an electric current flow between two electrodes. Microbial fuel cells function in much the same way except that the catalytic reactions are carried out by bacteria contained within the fuel-cell chamber. Under anae
20、robic conditions(where oxygen is absent), metabolising the fuel by feeding off it and in doing so produce natural chemical reactions that produce a current. In theory microbial fuel cells can run on almost any kind of organic matters, says Chris Melhuish, head of the Bristol Robotics Laboratory, Eng
21、land. “All you have to do is match the microbial culture with the type of stuff you want to use as fuel,“ he says. Dr Melhuish has been trying to power robots on domestic waste-water, but it is tricky. Ideally you would want to use cheap raw-waste products, he says. But traditionally the fuel cells
22、work best with a refined fuel in the form of solutions containing synthetic sugars, such as glucose. However, Dr Antonopoulou has now shown that, using a culture of bacteria obtained from her local waste-water plant, it is possible to get almost as much power from raw whey as from refined fuel, prov
23、ided the whey is diluted. The trouble is the power output still only amounts to milliwatts, barely enough to trickle-charge a cellphone. And working with raw waste water also presents challenges. Initially Dr Antonopoulou and her colleagues found that the coulombic efficiency of their cells-a measur
24、e of how many electrons produced actually flow into a circuit-was particularly low, at around just 2%. This turned out to be because a second set of microbes, within the whey itself, was absorbing them. So, by sterilizing the whey first to kill these other bugs they have now boosted the coulombic ef
25、ficiency to around 25%. 6 What is the main idea of the first paragraph? （ A） Fuel cells can be powered by cheese. （ B） Lactose rich in whey can generate an electric current （ C） Fuel cells can be powered by cheese for whey in it. （ D） The idea that fuel cells can be powered by cheese may seem ridicu
26、lous. 7 Which of the following may not benefit from microbial fuel cells? （ A） Feta facilities. （ B） Toy factories. （ C） Sewage plants. （ D） Breweries. 8 What is the function principle of microbial fuel cells? （ A） The catalytic reactions are carried out by bacteria contained within the fuel-cell ch
27、amber. （ B） The catalytic reactions are carried out by bacteria outside the fuel-cell chamber. （ C） The catalytic reactions are carried out by bacteria in the aerobic conditions. （ D） The catalytic reactions are carried out by bacteria via unnatural chemical reactions. 9 Why is the coulombic efficie
28、ncy of microbial fuel cells particularly low? （ A） Because it is difficult to work with raw waste water. （ B） Because the fuel is hard to obtain. （ C） Because the scientists havent got the technology to sterilize the bacteria in whey. （ D） Because another kind of microbes is absorbing the electrons
29、at the same time. 10 The best title of the passage may be_. （ A） Whey Can Pose Environmental Harzard （ B） The Whey to Greener Electricity （ C） Why the Whey Can Generate Electricity （ D） A Seemingly Ridiculous Research 10 Honeybee populations declined by 13.6% over the winter, according to a survey o
30、f beekeepers across England. Losses were most severe in the north-east, where the survey recorded a loss rate of 17.1%. Experts worry that the declines will affect plant productivity. There are also concerns that the declines, along with drought conditions in some area, will mean less English honey
31、this year. Martin Smith, president of the British Beekeepers Association, which carried out the survey, said: “If this was measured against similar losses in livestock, it would be seen as disastrous and there would be great concern on the knock-on impact of food prices.“ Beekeepers are puzzled by t
32、he decline because the cold winter and early spring should have favoured bees. They stay “clustered“ tightly in their hives when it is cold and dry, saving energy for spring foraging when the temperature rises about 12C. However, there is good news that the rate of colony loss has slowed. Four years
33、 ago, one in three hives was wiped out. Beekeepers suspect that poor nutrition is a likely cause of weakness in adult bees that makes them succumb to diseases spread by a parasitic mite. “The varroa mite is the number one reason why people lose bees, so the government needs to increase research to c
34、ure diseases caused by varroa,“ said Smith. “But a colony that has a good source of pollen and nectar will go into winter more strongly and better able to fend off disease.“ The association is calling on everyone who has a garden, small, to plant bee-friendly plants this summer. “It is really import
35、ant that there are flowering nectar-rich plants around in August, September and October to provide the nutrition thats needed so the bees can top up their stores of honey in the hive to see them through winter,“ said Smith. A campaign being launched next week to save all bees, spearheaded by Sam Rod
36、dick and Neal s Yard Remedies, pins the blame for the decline on pesticide. It will start a petition to hand to Downing Street in October to ban the use of a class of pesticides that has been implicated in bee deaths across the world. Roddick said, “These neonicotinoid pesticides penetrate the plant
37、 and indiscriminately attack the nervous system of insects that feed off them, disorientating bees, impairing their foraging ability and weakening their immune system, causing bee Aids. On current evidence, Italy, Germany and Slovenia have banned some varieties. In the UK, its up to the people to sh
38、ow the government that if there is any doubt that they are contributing to bee deaths, we need to ban them.“ A spokesman for the governments National Bee Unit said: “The UK has a robust system for assessing risks from pesticides and all evidence shows neonicotinoids do not pose an unacceptable risk
39、when products are used correctly, but we will not hesitate to act if presented with any new evidence.“ 11 What can we safely infer from the first paragraph? （ A） Many beekeepers dont continue their work in winter. （ B） Many honeybees fly to other countries in winter. （ C） A number of honeybees die f
40、rom the low temperature. （ D） Cold weather may pose adverse effect on honeybees. 12 Which of the following is not the reason of less honey in Britain according to scientists? （ A） Because the number of honeybees declines. （ B） Because the beekeepers become much less. （ C） Because the productivity of
41、 honey plant will decline. （ D） Because of the drought conditions in some areas in Britain. 13 What leads to bee Aids according to Roddick? （ A） The parasitic mites. （ B） A lack of nutrition. （ C） The neonicotinoid pesticides. （ D） The cold weather. 14 According to the bee experts, which is not the
42、possible cause of the decline of bee populations in this passage? （ A） The cold weather. （ B） The poor nutrition of bees. （ C） The varroa mites. （ D） The neonicotinoid pesticides. 15 What is the experts point towards the decline of bee populations in winter? （ A） They are indifferent to the phenomen
43、on. （ B） They feel puzzled towards the decline and put forward several possible causes. （ C） They are rational and they only persist on one possible reason. （ D） It is hard to say. 15 Living near airports might not only lead to residents suffering sleepless nightsthey could also have terrible weathe
44、r, scientists say. For aircraft increase the chances of snow and rain when they take off and land, an extraordinary study suggests. Apparently the effects of jet planes punching through clouds are similar to “cloud seeding“ operations, where ice crystal are created in the atmosphere to make it rain.
45、 The findings published in the respected academic journal Science are based on satellite images of clouds around airports and computer models of cloud behavior. The side-effect of flying is likely to be the most obvious around the worlds busiest airports, such as Heathrow where more than 1,200 plane
46、s land or take off every day. The phenomenon occurs when aircraft smash through clouds containing “super-cooled“ water or water that exists as droplets of liquid at temperatures of minus 10C or below. As an aero plane passes quickly through a cloud, the air behind the wings and propellers expands an
47、d cools quickly. These sudden drops in temperature can be enough to freeze droplets of super-cooled water turning them into a stream of ice crystal. Over time, ice crystals grow and affect neighboring drops of water, creating a hole in the cloud that expands for several hours and increases the chanc
48、es of snow or rain on the ground underneath. Dr Andrew Heymsfield, of the National Center for atmospheric Research in Boulder, Colorado, said aircraft increased the chances of snow when they punched holes in clouds after taking off and when they created “canals“ in clouds when descending. “Whether a
49、n airplane creates a hole or a canal in the clouds depends on its trajectory,“ he said. When they climb through a super-cooled cloud layer, they can just produce a hole. But when they fly level through the cloud layer, they can produce long canals.“ The study found that super-cooled cloud layers are found with 62 miles of the world s major airports at least five per cent of the time. The cloud seeding effects are more noticeablely closer to the north and south poles. The researchers looked at 20 satellite images of cloud cover with holes suspended ove
