[考研类试卷]考研英语（阅读）模拟试卷147及答案与解析.doc

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1、考研英语（阅读）模拟试卷 147 及答案与解析Part ADirections: Read the following four texts. Answer the questions below each text by choosing A, B, C or D. (40 points)0 On 28 March, scientists got a whiff of something strange in the air off a pier in San Diego, California. The atmosphere had suddenly become flush with r

2、adioactive sulfur(a light-yellow non-metallic solid)atoms. That sulfur, it turns out, had traveled across the Pacific from a nuclear power plant in Fukushima, Japan, that was shaken by the 11 March earthquake and the tsunami and aftershocks that followed. Now the same team has studied those radioact

3、ive winds to come up with the first estimate of damage to the plants cores at the height of the disaster.To cool fuel rods and spent fuel while stanching a total meltdown, responders pumped several hundred tons of seawater into three reactors at the Fukushima Dai-ichi nuclear power plant. The white-

4、hot rods fizzled off steam, which had to go somewhere. So workers vented it into the air.Meanwhile, across the Pacific, atmospheric scientist Antra Priyadarshi of the University of California, San Diego(UCSD), remembered a study she had read a while back: Following underwater nuclear bomb tests in t

5、he 1950s and 60s, physicists noticed that a heavy form of sulfursulfur-35had mushroomed. Nuclear reactions spit out lots of fast and therefore “hot“ particles called neutrons, which can then bang into abundant chloride ions in saltwater, converting them to sulfur-35. Priyadarshi and her colleagues w

6、ere already tracking tiny traces of radioactive sulfur to study how layers of air mix in the atmosphere, so all they had to do was wait.They didnt have to wait long. The sulfur was already swirling over Fukushima, where it had combined with oxygen to form sulfur dioxide gases and fine particles of s

7、ulfates called aerosols. Soon, strong winds pushed them west. Sulfur-35 does occur naturallycosmic rays zap argon atoms in the upper atmosphere, or stratosphere, to make radioactive sulfur. But little of it makes its way down to the lowest slice of atmosphere, called the marine boundary layer. On a

8、normal day, Priyadarshi sees between 180 and 475 sulfur-35 atoms as sulfates per cubic meter of air, but on the 28th, her team recorded about 1500. “No one has ever seen such a high percentage of the stratospheric air coming into the marine-bound layer,“ she says.The UCSD team ran a computer simulat

9、ion to trace the path of the gases and aerosols from Fukushima to the West Coast. Most sulfur -35 atoms likely dispersed or rained down into the sea before hitting San Diego, but Priyadarshi estimates that about 0.7% completed the trip, too few to become harmful. Based on the simulation, about 365 t

10、imes the normal levels of radioactive sulfates had gathered over Fukushima during the disaster.Now that Fukushimas reactors have cooled back down, the biggest challenge facing scientists will be to contain radioactive elements that escaped during the disaster. Mark Thiemens, the study co-author, an

11、atmospheric scientist who is also at UCSD, will be working with Japanese researchers to follow sulfur-35s path through soil and streams near Fukushima to find where even more harmful elements may have hidden.1 When did radioactive sulfur atoms appear at the west coast of America?（A）At the moment the

12、 earthquake and tsunami happened.（B） Before the tsunami attacked the east coast of Japan.（C） After the earthquake and the related disasters happened.（D）Two weeks after a nuclear power plant in Fukushima collapsed.2 It can be inferred from Priyadarshi that surfur-35 detected in America（A）was produced

13、 because of the seawater infused into the reactors in Fukushima.（B） was similar to that grew from the underwater nuclear test in the 1950s and 60s.（C） will mushroom as that derived from the underwater nuclear test half a century ago.（D）will spread widely and mix with air in different layers of atmos

14、phere.3 Priyadarshis comment on sulfur-35s appearing into the marine boundary layer implies that（A）natural sulfur-35 can also be found in the air above the sea.（B） the nuclear accident in Japan was its direct maker.（C） man-made sulfur-35 can exist in all layers of atmosphere.（D）natural sulfur-35 usu

15、ally exist in all layers but the marine boundary one.4 According to the computer simulation, sulfur-35 in Fukushima（A）must arrive at the west coast of America.（B） will cause psychological panic in people.（C） cannot affect Japanese peoples health.（D）cannot affect American peoples health.5 According t

16、o the passage, Mark Thiemens would devote himself to（A）tracking down how deep sulfur-35 can get into the soil.（B） locating the position of severely harmful elements.（C） calculating how many harmful elements have been produced.（D）detecting the route of sulfur-35 in order to eradicate it.5 Cancer aris

17、es when the descendants of just one of our more than ten thousand billion cells proliferate out of control, eventually interfering with normal body functions. Since so many cells are at risk, the most amazing thing about cancer to me is how many years it usually takes to develop the disease. One maj

18、or obstruction to the proliferation of cancerous cells is the phenomenon of apoptosis, which causes nearly all of our cells to kill themselves whenever they start to behave aberrantly.A complicated cellular signaling network determines the balance between the pro-apoptotic and anti-apoptotic protein

19、s inside animal cells. Each of our many cells is constantly sensing its external and internal environment and will sacrifice itself(for our own good)if it is either not correctly located or not behaving normally. Without mechanisms of this type, the evolution of large complex organisms such as ourse

20、lves would probably not have been possible, because the tumors caused by cancerlike diseases would have overtaken us early in life.Tumors arise after a long process of random mutation followed by multiple rounds of selection for those cells able to proliferate best. One change selected for is in apo

21、ptotic mechanisms, which will be altered in different ways in different tumors. Imagine that we could determine why the cells in an individuals tumor incorrectly compute that they need not kill themselves, as normal cells would do in their condition. If we understood the fundamental mechanisms by wh

22、ich cells make these decisions, we would stand an excellent chance of creating a tailored mixture of drugs that causes the tumor cells to compute differently, so that they commit suicide without harming normal cells.Another promising strategy takes advantage of the fact that essentially all cancer c

23、ells have acquired a defect in some aspect of their “DNA metabolism“ , often some aspect of DNA repair that causes them to become highly mutable. This genetic instability of cancer cells is selected for early in tumor development, because only such cells can evolve the multiple additional changes, i

24、ncluding defects in apoptosis, that are necessary for most cell types to become malignant.Cells that are too genetically unstable will die. Therefore, a treatment that blocks a particular DNA repair process can be lethal for a cancer cell, while sparing normal cells. If we could determine why the ce

25、lls in a particular individual tumor are genetically unstable, we might be able to design drugs that kill the cells in that cancer highly selectively, with little harm to normal cells.These examples of rational approaches to cancer therapy were only a dream until recently. But by targeting these typ

26、es of alterations in cancer cells, researchers have made impressive progress and are thus much closer to being able to design highly selective therapies based on the critical molecular defects in an individual tumor. But for most tumors, this type of approach is still hit or miss, because oncologist

27、s are severely hampered by an inadequate understanding of the fundamental processes that are altered in a particular tumor. 6 The word “apoptosis“(Line 5, Para.1)most probably means（A）appearing.（B） changing.（C） dying.（D）thriving.7 The function of the cellular signaling network is to（A）maintain a bal

28、ance between the internal and the external environment.（B） help enhance the protein within our body.（C） would overtake human beings early in life.（D）kill those ill-located or mal-functioned cells.8 We can learn from the third paragraph that（A）tumor will cause a long process of random mutation.（B） mu

29、ltiple rounds of selection can prevent proliferation.（C） normal cells would commit suicide if tumor-infectious.（D）its promising to make drugs that can kill tumor cells directly.9 It can be inferred from Paragraph 5 that we can cure cancer by（A）making the infectious cells unsteady in gene.（B） killing

30、 the cells in the patients body.（C） designing lethal medicine to change the gene of the body.（D）enhancing the DNA repair process.10 Which of the following is true according to the last paragraph?（A）The approaches mentioned in the passage has long been used to cancer.（B） Alterations in cancer cells i

31、s still an experimental approach to healing cancer.（C） Researchers can already design highly selective therapies to cancer treatment.（D）Oncologists have made a thorough research on the fundamental processes in tumors.10 The untrained eye might have trouble distinguishing the latest images from Mercu

32、ryreleased last week at a NASA press conference herefrom countless images of Earths moon, but dont tell that to Sean Solomon. Mercury “was not the place we expected,“ says Solomon, principal investigator of the MESSENGER mission to Mercury. “It was not the moon. “ The first close look at the innermo

33、st planet in 33 years and the first look ever at one-third of it revealed a new side to the innermost planet: much more volcanism than seen before, deeply excavating impact craters, andunique in the solar system“The Spider. “The Mariner 10 spacecraft last flew by Mercury in 1975, returning images su

34、ggesting that lava once flowed across the surface, at least in places. But volcanism “wasnt accepted by everyone ,“ says imaging team member Louise Prockter of Johns Hopkins Universitys Applied Physics Laboratory in Laurel, Maryland. Now, “theres very little doubt there has been widespread volcanic

35、resurfacing of Mercury. “ She pointed to impact craters hundreds of kilometers across with floors so smooth that they must have been partially filled by lava. Team member Robert Strom of the University of Arizona, Tucson, also found that the side of Mercury seen by Mariner 10 turns out to be more he

36、avily cratered by impacts than the side seen for the first time by MESSENGER. That means that lava has flooded the MESSENGER side even more extensively than the other side. “Theres been a lot of volcanic activity on Mercury,“ says Strom.The moon has its volcanic flooding, toowitness the dark “scars,

37、“ or maria, that shape the man(or woman)in the moonbut MESSENGER found a mercurial variation on such light-dark patterning. Caloris is a huge-1550-kilometer-wide-impact basin glimpsed by Mariner 10 but now seen in its entirety by MESSENGER. On the moon, such giant impact basins were often filled wit

38、h dark lava to form maria, but Caloris has the opposite pattern. Its interior is lighter and is surrounded by a darker ring. Perhaps the Caloris impact excavated deep, lighter-colored rock and left it at the surface without flooding it with lava, says Solomon, director of the Carnegie Institution of

39、 Washingtons Department of Terrestrial Magnetism in Washington, D. C. Including smaller craters with distinctive dark rims, “weve got a variety of natural drill holes into Mercurys interior,“ says Solomon.Then theres The Spider more than 50 troughs radiate from near the center of Caloris where a 40-

40、kilometer-wide crater has formed. Whether the crater has anything to do with the radiating troughs, Prockter cant say; no one has ever seen anything like The Spider. One possibility is that the formation of Caloris somehow created a plume of molten rock that rose beneath the basins center, bulging t

41、he basin floor upward and cracking the crust to form the troughs. The crater would then have been an accidental impact. MESSENGER returns in October for another look at Mercury on its way to entering orbit in 2011.11 Which of the following is true according to the first paragraph?（A）One may have dif

42、ficulty telling the images of Mercury from the images of the earths moon.（B） Sean Solomon was very angry that we find no difference among the images.（C） NASA is a famous space shuttle which sends back countless images from moon.（D）The Spider is another name of Mercury.12 We may infer from the second

43、 paragraph that（A）not all of us believed that there was volcanism in Mercury in the 1970s.（B） Louise Prockter and Robert Strom had opposite ideas about the volcanism in Mercury.（C） Robert Strom was the leader of the Applied Physics Laboratory.（D）MESSENGER flew by Mercury in the year of 1980.13 Which

44、 of the following is true according to the third paragraph?（A）The giant impact basins of the Caloris and that of the moon are all the same.（B） The giant impact basins of the Caloris are filled with dark lava to form maria.（C） MESSENGER found a new patterning of impact basin in Mercury.（D）Solomon fou

45、nd natural drill holes in the surface of the moon.14 We can learn from the fourth paragraph that（A）Prockter knows the relation between the crater and the radiating troughs.（B） the Spider is a unique phenomenon in the solar system.（C） the Spider is formed by the lava in Caloris.（D）another investigati

46、on will be done by Mariner 10 in the year 2011.15 Which of the following would be the best title for the passage?（A）Mercury and Moon（B） Spider in the Mercury（C） MESSENGER Reveals a More Active and Strange Mercury（D）The Story of MESSENGER15 Thanks to microbes, methane bubbles out of rice paddies and

47、escapes from the back ends of termites and the front end of cows. Over the years, researchers have gained a good handle on these and other sources of this potent greenhouse gas. But a report in the 12 January issue of Nature suggests that one source has been overlooked: plants. Although the surprisi

48、ng finding doesnt change the total amount of methane emitted to the atmosphere, it could force a reappraisal of how much various sources contribute, how to mitigate some of them, and how they might change. “This paper will shake the methane community,“ predicts Christian Franken-berg of the Universi

49、ty of Heidelberg, Germany.Methane is largely made by microbes. Living in oxygen-poor environments, they ferment organic matter or reduce carbon dioxide. Methane is also produced in massive quantities from wild and controlled fires and is released from natural gas leaks. But among biological processes, researchers had no idea that anything other than microbial anaerobic reduction was responsible.The clue for the new research came from chloromethane, a halogenated organic gas that avidly destroys ozone and was thought to come mainly from burning biomass.