1、专业英语八级（阅读）模拟试卷 91及答案与解析 SECTION A MULTIPLE-CHOICE QUESTIONS In this section there are several passages followed by fourteen multiple-choice questions. For each multiple-choice question, there are four suggested answers marked A , B, C and D. Choose the one that you think is the best answer. 0 (1)Wit
2、h the toll from anthrax mounting, the antibiotic most commonly used to tackle the deadly bug is now a celebrity. News anchor Tom Brokaw recently held a bottle up to the camera, saying: “In Cipro we trust.“ (2)Sadly, that trust could be short-lived. Cipro “may have the dubious distinction of being th
3、e antibiotic we destroy faster than any other“, warns microbiologist Abigail A. Salyers at the University of Illinois. The problem is that bacteria are immensely adaptable critters. Expose them to antibiotics long enough, and theyll evolve ways to survive the drugs. (3)Infectious-disease experts str
4、ess that people exposed to anthrax, such as postal workers in affected mail centers, should take Cipro, at least until tests show either that they dont have the bug or that their bacterial strain is susceptible to other drugs. But those who gulp down Cipro merely out of fear are being dangerously ir
5、responsible, putting both themselves and others at risk. (4)Why? The human body teems with bacteria. A broad-based antibiotic such as Cipro acts like a neutron bomb on this ecosystem, wiping out billions of microbes. Not only can that impair normal body functions in which bacteria play a role, such
6、as digestion, but harmful germs can move in, like squatters taking over suddenly vacant houses. (5)CRYING WOLF. Worse, antibiotics breed resistance. When you take a drug, the hardest bacteria among constantly mutating strains survive, reproduce, and pass along defense mechanisms against drugs. Takin
7、g Cipro for weeks “is the perfect situation for the regular bacteria in the body to become resistant“, says Dr. Carol J. Baker, a pediatrician at Baylor College of Medicine and president of the Infectious Disease Society of America. Except in the case of an actual anthrax infection rather than more
8、exposure its best to take the antibiotic for a few days only, to limit the development of resistance in the bodys bacteria. (6)Even without resistance, these normally harmless bugs can turn nasty. Painful infections result when benign gut flora, such as E. coli, find their way to the urinary tract.
9、Streptococcus bugs that live harmlessly in the throat cause pneumonia if they get into the lungs. Contract one of these diseases, and your doctor may prescribe Cipro. But if youve previously taken weeks of the antibiotic, your particular bug may already be primed to resist it. Not until you have to
10、rush to the hospital will anyone know that something has gone horribly wrong. And the resistant microbes can spread to others. (7)Indeed, antibiotic resistance is one of the worlds most pressing public-health problems. A single case of so-called multidrug-resistant tuberculosis costs more than $250,
11、000 to cure and the deadly germs are on the rise in many countries. Up to 30% of bacteria that cause ear infections and pneumonia in the U.S. can fight off standard antibiotics. The toll: thousands of hospitalizations and billions of dollars a year. (8)The quinolone drugs of which Cipro is one examp
12、le were once part of the solution. They kill a wide spectrum of bugs, including strains resistant to other drugs. But resistance to quinolones has appeared in everything from meningitis-causing pneumococcus bugs to the E. coli in bladder infections. 1 Which of the following statements can be inferre
13、d from the passage? （ A） Take Cipro often and get better soon. （ B） People dont trust in Cipro. （ C） The advantage of antibiotic. （ D） Cipro: now for the downside. 2 According to the passage, which of the following is NOT true? （ A） Regular bacteria in the body can become resistant to antibiotics. （
14、 B） One can take antibiotics for a long time so as to cure the disease. （ C） Antibiotic may destroy the functions of normal body. （ D） People need to pay more attention to the antibiotic resistance. 3 The authors attitude towards the overuse of antibiotics is _. （ A） Positive （ B） negative （ C） neut
15、ral （ D） indifference 3 (1)The winner takes all, as is widely supposed in computing circles. Indeed, geeks have coined a word, “Googlearchy“, for the way in which search engines encourage web traffic towards the most popular sites. The belief mat search engines make popular websites even more fashio
16、nable, at the expense of other pages, is now being challenged by research. (2)The apparently magical ability of search engines such as Google to return relevant websites even when given the sketchiest of clues by the person entering a question relies on the use of mathematical recipes or algorithms.
17、 Google works by analyzing the structure of the web itself. Each of its billions of pages can link to other pages and can also, in turn, be linked to by others. If a page is linked to many other pages, it is flagged up as being important. Furthermore, if the pages that link to this page are also imp
18、ortant, then that page is even more likely to be important. The algorithm has been made increasingly complex over the years, to deter those who would manipulate their pages to appear higher in their rankings, but it remains at the heart of Googles success. (3)Google is not alone in this. Many search
19、 engines take account of the number of links to a website when they return the results of a search. Because of this, there is a widespread belief among computer, social, and political scientists that search engines create a vicious circle that amplifies the dominance of established and already popul
20、ar websites. Page returned by research engines are more likely to be discovered and consequently linked to by others. (4)Not so, according to a controversial new paper that has recently appeared on ArViv, an online collection of physics and related papers. In it, Santo Fortunato and his colleagues a
21、t Indiana University in America and Bielefeld University in Germany claim that search engines actually have an egalitarian effect that increases traffic to less popular sites. (5)The researchers developed a model that described two extreme cases. In the first, people browsed the web only by surfing
22、random links. In the second, people only visited pages that were returned by search engines. The researchers then turned to the real world. To their amazement, they found that the relationship between the two did not lie between the extremes suggested by their model but somewhere completely differen
23、t. It appears to show that the supposed bias in favor of popular pages is actually alleviated by the combination of search engines and people following random links. (6)The paper, which was posted on ArViv for comment, has now come under attack. Matthew Hindman, a political scientist at Arizona Stak
24、e University, says that the data used in the research are pretty shoddy. Moreover, he says, the discrepancy between the model and the real world does not necessarily come from the role of the search engine. (7)Whether Dr. Fortunates thesis stands the test of time remains to be seen. That it is teste
25、d must be a good thing. 4 Whats the meaning of “deter“ in the second paragraph? （ A） Encourage. （ B） Dissuade. （ C） Delay. （ D） Support. 5 The foremost reason why Google is successful is no other than _. （ A） its magical ability of searching information （ B） its higher page rankings and complex webs
26、ites （ C） complexity of its algorithms over the years （ D） its heavy web traffic and difficult structure 6 Santo Fortunate and his colleagues seem to suggest that _. （ A） fair effect is created by increasing traffic to less well known sites （ B） popular websites are made more fashionable by search e
27、ngines （ C） the situation in favor of popular pages has become more serious （ D） popular pages are more likely to be discovered by random links 6 (1)Three decades after the first Apollo landing on the moon, the debate between proponents of manned and unmanned space missions has not changed a great d
28、eal. But many space scientists, who work with robotic satellites including me, have gradually moved from opposing human spaceflight to a more moderate position. In special situations, we now realized, sending people into space is not just an expensive stunt but can be more cost-effective than sendin
29、g robots. Mars exploration is one of those cases. (2)The basic advantage of astronauts is that they can explore Mars in real time, free of communications delays and capable of following up interesting results with new experiments. But the question arises: Where should the astronauts be? The obvious
30、answer on the surface of Mars is not necessarily the most efficient At the first “Case for Mars“ conference in 1981, one of the more provocative conclusions was that the Martian moons, Phobos and Deimos, could serve as comparatively inexpensive beachheads. (3)Most current mission scenarios involve a
31、 pair of spacecraft. The first positions propellants and other heavy components, such as spare modules and re-entry vehicle, on or near Mars. Because the journey time is not crucial, it can use electric propulsion and gravity-assist procedures to reduce the cost The story is rather different for the
32、 second spacecraft, which transports the astronauts. It must traverse Earths radiation belts rapidly, and to save on supplies, the transit time to Mars should be as short as possible. (4)The carious mission plans part ways when it comes to deciding what should happen once the crew ship and the freig
33、ht ship link up at the Red Planet. In order of increasing difficulty and expense, six possible scenarios are: a Mars flyby analogous to the early Apollo missions, with immediate return to Earth; a Mars orbiter, permitting a longer stay near the planet; a Phobos-Deimos(Ph-D)mission, involving a trans
34、fer to a circular, equatorial orbit, with a landing and base on a Martian moon, preferably Deimos; a hybrid mission(Ph-D-plus)that adds a brief sortie to the Martian surface; a full-scale Martian landing, with a longer stay on the surface and a complete program of research; and finally, an extended
35、stay on Mars, during which astronauts erect permanent structures and commence continuous habitations of the planet. (5)The trick will be to make sure the first manned mission is ambitious the adventure is, after all, part of the attraction but not too ambitious, lest it not win funding. The Ph-D and
36、 Ph-D-plus missions offer a compelling balance of cost and benefit and would provide the greatest return for science. (6)Deimos would offer an excellent base for the study of Mars. From there the astronauts could deploy and control atmospheric probes, subsurface penetrators and rover vehicles all ov
37、er the Martian surface. The moons near-synchronous orbit permits direct contact with a rover for about 40 hours at a time. Phobos, being closer to the planet, orbits faster and therefore lacks this particular advantage. But astronauts on either moon could analyze returned samples without fear of con
38、taining Earth with any Martian life-forms. (7)The ready availability of a vacuum would make it easier to operate laboratory instruments such as mass spectrometers and electron microscopes. By relocating the spacecraft to different locations on Deimos an easy task in the minuscule gravityastronauts c
39、ould protect themselves from solar storms and meteor streams. Besides, the moons are fascinating bodies in their own right; direct sampling would investigate their mysterious origins. (8)In comparison, an operating base on the surface of Mars would suffer many handicaps. Rovers deployed elsewhere on
40、 the planet would still have to be operated by remote control, which would require a satellite communications system to relay the commands. Returning samples from distant locations to the base would be more difficult. Heavy backup batteries or nuclear generators would be needed to power the base at
41、night or during dust storms. (9)In the more distant future, the moons could serve as way stations for descent to or ascent from the surface via tethers. Scientists on Deimos could safely direct large-scale climatological experiments, such as altering weather patterns or melting the polar capsthereby
42、 testing techniques for terraforming Mars or mitigating climate change on Earth. (10)Although the costs and benefits of various mission scenarios are difficult to analyze at this early stage, I conducted a poll of Mars mission experts during a conference several years ago. It offers the full spectru
43、m of science more cheaply and quickly, and it would set the stage for an eventual base and colony on the surface. 7 Which of the following is NOT the characteristic of manned mission? （ A） A proper landing site has already been chosen. （ B） Astronauts have the ability of exploring Mars in real time.
44、 （ C） There is no communications delays on the road. （ D） Astronauts design new experiments with interesting results. 8 Which of the following is INCORRECT as for the advantage of Ph-D and Ph-D-plus mission? （ A） Astronauts can analyze samples safely on Deimos and Phobos. （ B） Vacuum can protect ast
45、ronauts from solar and meteor storms. （ C） Astronauts have no difficulties when landing on Mars surface. （ D） Astronauts may suffer many handicaps on the surface of Mars. 9 What is the most appropriate title of this article? （ A） Mars and its Moons （ B） To Mars by way of its Moons （ C） Ambitious adv
46、enture: worth （ D） What its like on Mars 9 (1)As humankind moves into the third millennium, it can rightfully claim to have broken new ground in its age-old quest to master the environment. The fantastic achievements of modern technology and the speed at which scientific discoveries are translated i
47、nto technological applications attest to the triumph of human endeavour. (2)At the same time, however, some of these applications threaten to unleash forces over which we have no control. In other words, the new technology Man now believes allows him to dominate this wider cosmos could well be a Fra
48、nkenstein monster waiting to turn on its master. (3)This is an entirely new situation that promises to change many of the perceptions governing life on the planet. The most acute challenges facing the future are likely to be not only those pitting man against his fellow man, but those involving huma
49、nkinds struggle to preserve the environment and ensure the sustainability of life on earth. (4)A conflict waged to ensure the survival of the human species is bound to bring humans closer together. Technological progress has thus proved to be a double-edged sword, giving rise to a new form of conflict: a clash between Man and Nature. (5)The new conflict is more dangerous than the traditional one between man and his fellow man, where the protagonists at least shared a common language. But when it comes to the reactions of the ecosystems to
