大学六级-1606及答案解析.doc

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1、大学六级-1606 及答案解析(总分：667.00，做题时间：90 分钟)一、Part Writing(总题数：1，分数：106.00)1.大学生刷信用卡消费已成普遍现象；2. 大学生过度使用信用卡可能带来哪些问题；3. 停止向大学生发放信用卡的理由和好处。（分数：106.00）_二、Part Reading Compr(总题数：1，分数：70.00)HIV 60 to 70% of those are in Sub-Saharan Africa. But the disease is spreading in every region, with fierce epidemics threa

2、tening to tear through countries such as India, China, Russia and the islands of the Caribbean. The statistics are sobering in some Southern African towns 44% of pregnant women are HIV positive, in Botswana 37% of people carry the virus.Immune assassinThe human immunodeficiency virus (HIV) is a retr

3、ovirusa virus built of RNA instead of more typical DNA. It attacks the very cells of the immune system that should be protecting the body against it F lymphocytes and other white blood cells with CD4 receptors on their surfaces. The virus uses the CD4 receptor to bind with and thereby enter the lymp

4、hocyte. HIV then integrates itself into the cells own DNA, turning the cell into a virus-generating factory. The new viruses break free, destroying the cell, then move on to attack other lymphocytes.HIV kills by slowly destroying the immune system. Several weeks after initial infection, flu-like sym

5、ptoms are experienced. Then the immune system kicks-in, and the virus mostly retreats into hiding within lymph tissues. The untreated, infected individual usually remains healthy for 5 to 15 years, but the virus continues to replicate in the background, slowly obliterating the immune system.Eventual

6、ly the body is unable to defend itself and succumbs to overwhelming opportunistic infections that rarely affect healthy people. Acquired Immune Deficiency Syndrome (AIDS) is the name given to this final stage of HIV infection, and is characterized by multiple, life-threatening illnesses such is weig

7、ht loss, chronic diarrheoa, rare cancers, pneumonia, fungal conditions and infections of the brain and eye. Tuberculosis has become especially prevalent in AIDS victims.Natural born killerGenetic analyses hint that ancestral primate HIV may have been born a million years ago when a chimpanzee virus

8、hybridized (杂交) with a related monkey variety. However researchers believe it was not until the 1930s that this jumped to humans eating chimp meat in Central Africa. That variety became HIV-1 the most widespread type. A second type, HIV-2, restricted to West Africa, was probably contracted in the 19

9、60s from monkey meat.Another theory was that the AIDS pandemic was accidentally started by doctors testing a polio vaccine in the 1950sdetailed in Edward Hoopers book The River but this has been severely criticized by other researchers.AIDS must have been circulating in the US and Africa during the

10、1970s. But it was not recognized until 1981 when young gay men and injecting drug users, in New York and California, started to be diagnosed with both an unusual skin cancer called Kaposis sarcoma, and lethal pneumonias. By the end of that year 121 people in the US had died that number would rise to

11、 17,000 over the next six years.Government scientists predicted that the mysterious immune-debilitating illness was due to an infectious agent. In 1984 that agent was identified as HIV by Luc Montagnier of the Pasteur Institute in Paris, France, and Robert Gallo of the National Cancer Institute in W

12、ashington DC, US.Soon after the appearance of AIDS in the US, the disease was detected in Europe too and epidemics affecting heterosexual men and women sprang up at an alarming rate in Sub-Saharan Africa. Today one in five people in that region are living with the virus. AIDS epidemics also threaten

13、 to devastate the worlds most populous nations India and China if action is not taken to bring them under control. Defensive measuresHIV is found in body fluids such as: blood, semen, vaginal fluids and breast milk. It can be passed on through penetrative sex, oral sex and sharing contaminated needl

14、es when injecting street drugs or in hospitals. It can also be transmitted from a mother to her baby during pregnancy, childbirth or breastfeeding though many children escape infection. HIV cannot be passed on through kissing, coughing, mosquito bites or touching.Health authorities are focusing on p

15、revention as a key method to limit the spread of the epidemic. Educational programs preach abstinence from sex, monogamy and safer sex using condoms, as ways to protect against infection. Many countries give away free condoms and offer needle exchange programs to try and limit transmission among inj

16、ecting drug users. Microbicides in the form of creams that prevent transmission of HIV may soon offer another method of protection.A vaccine, as an alternative method to prevent HIV infection, may still be many years away. This is partly because the virus mutates so rapidly. A vaccine may not only h

17、ave to prime antibodies to attack the virus (the way most vaccines work) but might also need to increase T-cell production. Vaccine trial; have been undertaken in South Africa, Kenya, the US and Thailand though most have yet to yield promising results. Controversial vaccines made from the blood of H

18、IV carriers, have been tested is Nigeria and Thailand.Anti-retroviral cocktailsThere is no cure for AIDS, but a range of drugssome of which have unpleasant side-effectsare available to slow, its progress. Other drugs are used to treat opportunistic infections or AIDS symptoms. Even some herbal treat

19、ments have been investigated.Most anti-HIV drugs aim at stalling viral replication. Nucleoside analogues such as AZT (zidovudine) and also non-nucleoside reverse transcriptase inhibitors (NNRTIs) (非核苷类逆转录酶抑制剂), attack the action of the viral enzyme reverse transcriptase. This prevents it from creati

20、ng functional DNA which would otherwise integrate into the DNA of infected cells.A third class block protease, an enzyme essential for generating functional virus particles. Protease inhibitors are the most effective of the three types of drugs, and AIDS mortality fell dramatically in the US when th

21、ey were first licensed during the late 1990s. Fusion inhibitors are a newer type of drug that work by stopping HIV from binding with CD4 receptors that it uses to enter cells. Drugs that block another enzyme, integrase (整合酶), are also under development.AIDS drugs are often administered in combinatio

22、n cocktails of three or more kinds simultaneously, as this helps slow the rate at which HIV develops resistance to drugs. But the virus is able to evolve rapidly and can eventually outpace the drugs if treatment regimens are not followed rigorously.Though drugs are widely available in Western countr

23、ies, their expense means they are unavailable to the vast majority of AIDS sufferers. International bodies are working towards widening access to treatment in the developing world. Some companies in countries such as India and Thailand are now producing cheap generic copies of drugs.Staggering tollT

24、he economic and social burden of AIDS exerts a great toll on developing nations in addition to that exerted by mortality itself. AIDS is hindering development and leading to negative population growth in some of the most seriously affected nations, such as Botswana.This excessive AIDS mortality is c

25、ausing a great demographic shift, wiping out young adults in the prime of their lives. This leaves children orphaned, and is destroying workforces and economies. Some predict that 50 million children in Sub-Saharan Africa will have been orphaned by 2010. The labor forces of 38 AIDS ravaged countries

26、 will be up to 35% smaller by 2020, because of AIDS.The effect of AIDS on agricultural communities in Southern Africa is even leading to food shortages. Social stigma and discrimination is yet another problem for many AIDS sufferers, especially in Asian nations.（分数：70.00）(1).What can we learn about

27、AIDS from the first two paragraphs?A. People killed by it are the same in number with the people being infected with HIV.B. It poses serious problems to human beings development both in medical and in social sense.C. Most of the people killed by it are from the developing world.D. 44% of women are H

28、IV positive in some Southern African towns.（分数：7.00）A.B.C.D.(2).How does HIV turn the cell of the immune system into a virus-generating factory?A. It breaks into the cell and reproduces itself.B. It uses the CD4 receptor to bind with the RNA of the cell.C. It integrates into the DNA of infected cell

29、s.D. It destroys the cells RNA and multiplies inside it.（分数：7.00）A.B.C.D.(3).Several weeks after being infected with HIV, a person will_.A. lose their weight B. experience flu-like symptomsC. cant work anymore D. have a poor appetite（分数：7.00）A.B.C.D.(4).The American people recognized AIDS first when

30、 young gay men and injecting drug users_.A. were diagnosed with an unusual skin cancer and lethal pneumoniasB. died of rare cancersC. started chronic diarrheaD. experienced flu-like symptoms（分数：7.00）A.B.C.D.(5).HIV can be transmitted between two individuals by the way of_.A. mosquito bites B. touchi

31、ng C. injecting D. coughing（分数：7.00）A.B.C.D.(6).In order to limit the spread of the epidemic, health authorities are_.A. focusing on prevention B. making efforts to develop vaccinesC. trying to find cure D. forbidding people to eat chimp meat（分数：7.00）A.B.C.D.(7).It will take many years to develop ef

32、fective vaccines to prevent HIV infection, partly because_.A. not all the countries are concerned about HIVB. the results of vaccine trials disappoint researchersC. there are other methods to prevent HIV infectionD. the virus mutates so rapidly（分数：7.00）A.B.C.D.(8).Most anti-HIV drugs aim at _.（分数：7.

33、00）填空项 1:_(9).Cocktails refer to the AIDS drugs that are often administered _ simultaneously, as this helps slow the rate at which HIV develops resistance to drugs.（分数：7.00）填空项 1:_(10).Besides the threat of death, another problem for many AIDS sufferers, especially in Asian nations, is_.（分数：7.00）填空项

34、 1:_三、Part Listening Com(总题数：0，分数：0.00)四、Section A(总题数：4，分数：105.00)(1).A. He refused to drive her. B. He is glad to drive her.C. He forgot his driving license. D. He has a new car.（分数：7.00）A.B.C.D.(2).A. She paid by check. B. She decided to make the purchase.C. She paid by credit card. D. She left w

35、ithout paying.（分数：7.00）A.B.C.D.(3).A. Call a friend. B. Work on his car.C. Take a taxi. D. Walk to work.（分数：7.00）A.B.C.D.(4).A. They will sail to San Francisco. B. They will fly to San Francisco.C. They will drive to Saan Francisco. D. They will take a train to San Francisco.（分数：7.00）A.B.C.D.(5).A.

36、Its not important how he dances. B. Its too crowed to dance anyway.C. If hes careful, no one will notice. D. No one knows the steps to the dance.（分数：7.00）A.B.C.D.(1).A. Sailing a boat. B. Catching a worm. C. Fishing. D. Hanging clothes.（分数：7.00）A.B.C.D.(2).A. She doesnt like the film. B. The film is

37、 hard to understand.C. She saw the film from beginning to end. D. She only saw the last part of, the film.（分数：7.00）A.B.C.D.(3).A. We learned that Mary is going to Hawaii.B. We learned that Mary has traveled all over the world.C. We learned that Mary like postcards.D. We learned that Mary is going on

38、 vacation.（分数：7.00）A.B.C.D.Questions 19 to 22 are based on the conversation you have just heard,（分数：28.00）(1).A. She doesnt want to pay the late fee.B. She was given incorrect information.C. She cant afford to pay her tuition.D. She didnt pass her mathematics class last semester.（分数：7.00）A.B.C.D.(2)

39、.A. The director couldnt give her an appointment right away.B. The office was closed the first time she went.C. The computers were out of service the first time she was there.D. She did not have acceptable identification with her on her first visit.（分数：7.00）A.B.C.D.(3).A. Her prior schooling. B. Her

40、 residence. C. Her age. D. Her driving record.（分数：7.00）A.B.C.D.(4).A. The director probably isnt able to make an exception.B. The director probably wont see her.C. The director usually isnt very helpful.D. Part-time students arent the directors responsibility.（分数：7.00）A.B.C.D.Questions 23 to 25 are

41、based on the conversation you have just heard.（分数：21.00）(1).A. Chicago. B. New York. C. Boston. D. Detroit.（分数：7.00）A.B.C.D.(2).A. In a little while. B. First thing in the morning.C. Pretty quick. D. By 8:00.（分数：7.00）A.B.C.D.(3).A. An Elgin. B. A Rolex. C. A Seiko. D. A Bulova.（分数：7.00）A.B.C.D.五、Sec

42、tion B(总题数：3，分数：70.00)Questions 26 to 28 are based on the passage you have just heard.（分数：21.00）(1).A. The meaning of facial expressions depends on situations.B. Facial expressions can cause misunderstanding across culture.C. People from one culture may lack facial expressions because they experienc

43、e less emotion.D. Facial expressions may disguise true feelings.（分数：7.00）A.B.C.D.(2).A. They smile to cover embarrassment. B. It is an unusual and even suspicious behavior.C. They smile to show politeness. D. It is an expression of pleasure.（分数：7.00）A.B.C.D.(3).A. We shouldnt judge people by reading

44、 their faces.B. We shouldnt smile in the wrong place.C. We shouldnt cover our true feelings.D. We shouldnt express our emotions too openly.（分数：7.00）A.B.C.D.Questions 29 to 31 are based on the passage you have just heard.（分数：21.00）(1).A. Separate houses were built for storing ice.B. Double walls were

45、 built in icehouses to keep cool.C. Blocks of ice were packed with weed in icehouses.D. Ice was put into icehouses in winter.（分数：7.00）A.B.C.D.(2).A. The ice was cut and handled with the help of some special tools.B. The ice was taken from the flowing river with hooks and carried by sleds to icehouse

46、s.C. The ice was carried on the frozen surface of the pond or river.D. The ice was sawed into even blocks by workers.（分数：7.00）A.B.C.D.(3).A. Ice Saws, choppers, axes, tongs, hooks. B. Ice Axes, saws, choppers, tongs, hooks.C. Choppers, axes, saws, hooks, tongs. D. Ice Axes, saws, choppers, hooks, to

47、ngs.（分数：7.00）A.B.C.D.Questions 32 to 35 are based on the passage you have just heard.（分数：28.00）(1).A. To find out how much air can be pumped into a plane.B. To find out how much air passengers need to breathe at certain altitudes.C. To find what would happen if the plane crashed in the water.D. To f

48、ind out if there are any weak parts in the plane that would burst under pressure.（分数：7.00）A.B.C.D.(2).A. Because the water pressure is greater than air pressure.B. Because the first Comets crashed in the water.C. Because there is less damage when the explosion takes place under water.D. Because it i

49、s the only way available for engineers to find out which part has cracked.（分数：7.00）A.B.C.D.(3).A. In the air. B. On the airfield.C. Under water. D. At plane manufacturing factory.（分数：7.00）A.B.C.D.(4).A. Two important tests of a new airliner because it is put into use.B. How to carry out tank test in the water.C. How pilots carry out the test flights.D. How to make a