2009年全国医学博士外语统一考试英语试卷
试卷一（Paper One）
Part ⅠListening Comprehension（30%）
Section A
Directions：In this section you will hear ffteen short conversations between two speakers.At the end of each conversation，you will hear a question about what is said.The question will be read only once.After you hear the question，read the four choices marked A，B，C and D. Choose the best answer and mark the letter of your choice on the ANSWER SHEET.
Listen to the following example.
You will hear：
Woman：I feel faint.
Man：No wonder.You haven’t had a bite all day.
Question：What’s the matter with the woman？
You will read：
A.She is sick. B.She is bitten by an ant.
C.She is hungry. D.She spilled her paint.
Here C is the right answer.
Sample Answer
A B●D
Now let’s begin with question number 1.
1.A.John failed the exam. B.John didn’t take the exam.
C.John passed the exam，but scored low D.It took John a long time to pass the exam.
2.A.To travel by train. B.To go by taxi.
C.To go hiking. D.To rent a car.
3.A.1231-555-1212. B.1213-555-2112.
C.1213-555-1212. D.1231-555-2112.
4.A.Morning sickness. B.A frequent headache.
C.A pain in her right leg. D.A boring hospitalization.
5.A.Doctor and patient. B.Boss and secretary.
C.Agent and customer. D.Driver and passenger.
6.A.To buy another pair of shoes. B.To help his brother right away.
C.To turn to his brother for help. D.To seek advice from the woman.
7.A.He is offering a piece of advice. B.He is examining a patient.
C.He is attending his daughter. D.He is taking a patient’s history.
8.A.To ask the man to call her back. B.To go to the botanic garden.
C.To do some gardening. D.To play tennis.
9.A.Louise is not a new comer. B.Louise loves being a nurse.
C.Louise did a lot of work for the man. D.Louise has been waiting for a long time.
10.A.Two. B.Three.
C.Four. D.Seven.
11.A.She has thrown out of the car. B.She was knocked down by the car.
C.She hit her head on the steering wheel. D.She got the steering wheel in her chest.
12.A.She overacted to the man. B.She cried over her failure.
C.She made a success of her diet. D.She was jealous of the man.
13.A.He hates those who fool around. B.He will never try the stuff.
C.He will shoot any drug dealer. D.He regrets having tried the stuff.
14.A.The opposite to the man’s expectation. B.A quicker recovery than expected.
C.A pair of mismatching boots. D.Her healthy pregnancy.
15.A.He will do as requested. B.He will not join the team.
C.The woman is crazy about him. D.The woman has trouble standing.
Section B
Directions：In this section you will hear one dialogue and two passages.After each one，you will hear fve questions.After each question，read the four choices marked A，B，C and D.Choose the best answer and mark the letter of your choice on the ANSWER SHEET.
Dialogue
16.A.For the purpose of diagnosis confrmation.
B.For the possibility of legal trouble.
C.For the doctor’s investigation.
D.For the patient’s future use.
17.A.He has got cancer in his pancreas. B.He falls with a stomach problem.
C.He suffers from fatigue. D.He has a loss of weight.
18.A.See a dietician. B.Have an operation.
C.Start chemotherapy. D.Take medication for pain reliever.
19.A.A couple of years. B.More than 5 years.
C.A couple of months. D.Approximately 5 years.
20.A.Suspicious. B.Anxious.
C.Hesitant. D.Factual.
Passage One
21.A.Life evolution. B.Space exploration.
C.Extraterrestrial life. D.Unknown fying objects.
22.A.His 50th birthday.
B.NASA’s 50th anniversary.
C.The University’s 50th anniversary.
D.The US Cosmology Association’s 50th Anniversary.
23.A.Even primitive life is impossible. B.Intelligent life is fairly common.
C.Intelligent life is less likely. D.Any form of life is possible.
24.A.Nuclear weapons. B.Alien kidnapping.
C.Human extinction. D.Dangerous infection.
25.A.Ironic. B.Negative. C.Indifferent. D.Supportive.
Passage Two
26.A.Obese people need more food. B.Obese people require more fuel.
C.Obesity contributes to global warming. D.Obesity is growing as a global phenomenon.
27.A.Limited living space.
B.Crowded shopping malls.
C.Food shortage and higher energy prices.
D.Incidence of diabetes and cardiovascular diseases.
28.A.Over 700 million. B.Over 400 million.
C.Over 2.3 billion. D.Over 3 billion.
29.A.1，800 calories. B.1，280 calories.
C.1，680 calories. D.2，960 calories.
30.A.Climate change. B.The fall of food prices.
C.A rise in energy prices. D.An increasing demand for food.
Part ⅡVocabulary（10%）
Section A
Directions：In this section all the sentences are incomplete.Beneath each of them are given four words or phrases marked A，B，C and D.Choose the word or phrase that best completes the sentence.Then，mark the letter of your choice on the ANSWER SHEET.
31.The____conditions and places are likely to cause diseases.
A.unsanitary B.insidious C.insane D.ineffcacious
32.The witness was____by the judge for failing to answer the question.
A.abstained B.acquitted C.admonished D.adduced
33.He has____two cars this year because of traffc accidents.
A.pulled off B.worn out C.passed out D.written off
34.People are much better informed since the____of the Internet.
A.convenient B.advent C.interface D.aftermath
35.All instruments that come into contact with the patient must be____before being used by others.
A.sterilized B.labeled C.quarantined D.retained
36.By adopting this cunning policy，the clinic risks____many of its patients.
A.acquitting B.allocating C.alleviating D.alienating
37.Humor can also be a powerful____against stress and misfortune.
A.bravery B.blossom C.buffer D.buffet
38.Diabetes upsets the____of sugar，fat and protein.
A.metastasis B.metabolism C.malaise D.maintenance
39.The muscular____can affect the way we feel mentally.
A.potency B.fber C.lethargy D.synthesis
40.Evidence is widespread that HIV-infected persons slow to____their unsafe behavior.
A.respond to B.refect on C.wipe out D.put off
Section B
Directions：Each of the following sentences has a word or phrase underlined.Beneath each sentence there are four choices marked A，B，C and D.Choose the word or phrase which can best keep the meaning of the original sentence if it is substituted for the underlined part.Then mark the letter of your choice on the ANSWER SHEET.
41.Memory can be both enhanced and impaired by use of drugs.
A.inhibited B.injured C.induced D.intervened
42.Is it true that is the major drawback of the new medical plan？
A.defect B.assistance C.culprit D.triumph
43.The physician was becoming exasperated with all the questions they were asking.
A.frustrated B.perplexed C.irritated D.crippled
44.We were shocked at the physician’s callous disregard for the human dimension of medicine.
A.involuntary B.apparent C.deliberate D.indifferent
45.For years，biologists have known that chimpanzees and even some monkeys produce a panting sound akin to human laughter.
A.rocking B.gasping C.vibrating D.resonating
46.Everybody at the party was in a very relaxed and jolly mood.
A.rejoicing B.reconciling C.refreshing D.resenting
47.The bacterial infection is curable with judicious use of antibiotics.
A.impudent B.imprudent C.purulent D.prudent
48.He tried to run，but he was hampered by his broken leg.
A.endangered B.endured C.encountered D.encumbered
49.The whole holiday was a colossal waste of money.
A.consecutive B.conductive C.considerate D.considerable
50.The idea of correcting defective genes is not particularly controversial in the scientifc community.
A.inevitable B.applicable C.disputable D.incredible
PART ⅢCloze（10%）
Directions：In this section there is passage with ten numbered blanks.For each blank，there are four choices marked A，B，C and D listed beside the passage.Choose the best answer and mark the letter of your choice on the ANSWER SHEET.
Every day，over a million people log onto
different Internet-based games.There is truly something for everyone in the gaming world.Games provide a quick escape from 51 .Game developers are the new breed of storytellers，creating alternative 52 .Games represent the ultimate interactive movie，allowing the user to control the direction of the plot.
And now the newest technologies allow you to play games no matter where you are.At home，we have PC or video game consoles. 53 ，a desktop or laptop computer can be loaded with OS-bundled games or Web-based freebies.Even while traveling，there are many wireless computers，portable devices，wireless phones and PDAs 54 .
Games are now pushing back all the 55 once placed upon them by technology，category，realism，location and time.These advances are helping to push games into the 56 of virtual reality.Thus，the stuff of science fiction novels is gradually emerging，the graphic aspects of the game quickly 57 .Initially，electronic games involved 58 moving blocks across a TV or computer screen. 59 the vast increases in processing power，games are quickly approaching three-dimensional realism.This power allows a developer to create a 60 world where a gamer can look around in full 360-degree vision.
51.A.society B.reality
C.dream D.illusion
52.A.approaches B.characters
C.worlds D.mazes
53.A.In general B.At present
C.In reality D.At work
54.A.to choose from B.to choose
C.choosing from D.chosen
55.A.defects B.drawbacks
C.limitations D.disadvantages
56.A.room B.realm
C.range D.boundary
57.A.evolves B.evolving
C.evolved D.evolve
58.A.simply B.readily
C.exceptionally D.simultaneously
59.A.Aiding by B.To aid by
C.Aided by D.To be aided by
60.A.human B.original
C.realistic D.microscopic
Part ⅣReading Comprehension（30%）
Directions：In this part there are six passages，each of which is followed by fve questions.For each question there are four choices marked A，B，C and D.Choose the best answer and mark the letter of your choice on the ANSWER SHEET.
Passage One
Too much alcohol dulls your senses，but a study in Japan shows that moderate drinkers have a higher IQ than teetotalers.
Researchers at the National Institute for Longevity Sciences in Aichi Prefecture，250 kilometers west of Tokyo，tested the IQs of 2，000 people between the ages of 40 and 79.They found that，on average，men who drank moderately—defned as less than 540 milliliters of sake or wine a day—had an IQ that was 3.3 points higher that men who did not drink at all.Women drinkers scored 2.5 points higher than female teetotalers.
The type of alcohol didn’t influence the results.The volunteers tried a variety of tipples，which ranged from beer and whisky to wine and sake.
The researchers are quick to point out that the results do not necessarily show that drinking will make you more intelligent.
“It’s very diffcult to show a cause-effect relationship，”says senior researcher Hiroshi Shimokata.“We screened subjects for factors such as income and education，but there may be other factors such as lifestyle and nutritional intake.”
Shimokata says that people who drink sake，or Japanese rice wine，tend to eat more raw fsh.This could be a factor in enhanced intelligence，as fsh often contain essential fatty acids that have been linked to brain development.Similarly，wine drinkers eat a lot of cheese，which is not something Japanese people normally consume or buy.Shimokata says the high fat content of cheese is thought to be good for the brain.
If alcoholic drinks are directly infuencing IQ，Shimokata believes chemicals such as polyphenols could be the critical factor.They are known to have antioxidant properties and other benefcial effects on ageing bodies，such as dilating constricted coronary arteries.
The study is part of a wider research project to fnd out why brain function deteriorates with age.
61.The Japanese study was carried out on____.(https://www.daowen.com)
A.the development of IQ B.the secret of longevity
C.the brain food in a glass D.the amount of healthy drinking
62.The Japanese researchers found a higher IQ in____.
A.female teetotalers than in male ones B.female drinkers than in male ones
C.moderate drinkers D.teetotalers
63.When he says that it is very diffcult to show cause-effect relationship，Shimokata means that____.
A.the study failed to involve such variables as income and education
B.he is doubtful of the fndings of the investigation
C.there are some other contributing factors
D.the results were just misleading
64.From Shimokata’s mention of fsh and cheese we can infer that in enhancing intelligence____.
A.sake or wine is a perfect match for fsh and cheese
B.they promote the drinking effect of sake or wine
C.they are not as effective as sake and wine
D.sake or wine is not alone
65.Based on the study，Shimokata would say that____.
A.intelligence improves with age
B.IQ can be enhanced in one way or another
C.polyphenols in alcohol may boost the brain
D.alcoholic drinks will make you more intelligent
Passage Two
Women do not avoid fghting because they are dainty or scared，but because they have a greater stake than men in staying alive to rear their offspring.Women compete with each other just as tenaciously as men，but with a stealth and subtlety that reduces their chances of being killed or injured，says Anne Campbell of the department of psychology at the University of Durham.
Across almost all cultures and nationalities，men have a much smaller role than women in rearing children.“Males go for quantity of children rather than quality of care for offspring，which means that the parental investment of women is much greater，”says Campbell.And unlike men，who can’t be sure that their children have not been fathered on the sly by other men，women can always be certain that half an offspring’s genes are theirs.
Women have therefore evolved a strong impulse than men to see their children grow up into adults.Men’s psychological approach is geared to fathering as many children as possible.
To make this strategy work and to attract partners，men need to establish and advertise their dominance over rival males.Throughout evolution this has translated into displays of male aggression，ranging in scale from playground fghts to world wars.
Men can afford to take more risks because as parents they are more expendable.Women，meanwhile，can only ensure reproductive success by overseeing the development of their children，which means avoiding death.
“The scale of parental investment drives everything，”says Campbell.“It’s not that women are too scared to fght，”she says.“It’s more to do with the positive value of staying alive，and women have an awfully big stake not just in offspring themselves but in offspring they might have in the future，”she says.
This means that if women do need to compete—perhaps for a partner—they choose low-risk rules of engagement.They use indirect tactics，such as discrediting rivals by spreading malicious rumors.And unlike men who glory in feats of dominance，women do better by concealing their actions and their“victories”.
But there is no doubt，says Campbell，that the universal domination of culture by males has exaggerated these differences in attitudes to physical aggression.“The story we’ve always been told is that females are not aggressive，”says Campbell.And when they are aggressive，women are told that their behavior is“odd or abnormal”.
66.For the sake of their children，according to Campbell，women____.
A.are reluctant to start wars
B.cannot avoid being dainty or scared
C.would rather get killed or injured in fghting
D.do not fght with men under any circumstances
67.It can be learned from the passage that men and women____.
A.present different family values in the world
B.show defnite differences in parenting skills
C.are genetically conditioned in educating their children
D.take different psychological approaches to their children
68.Which of the following would men most probably be concerned about according to the passage？
A.Life. B.Parenting. C.Dominance. D.Reproduction.
69.To avoid death，women____.
A.cannot afford to confront risks
B.choose to fght in a violent way
C.try to seek protection from men
D.would resort to the“odd or abnormal’’tactics
70.What is the main idea of the passage？
A.Why men and women possess different parenting skills.
B.Why men are more aggressive than women.
C.Why women evolve in their own way.
D.Why women do not start fghts.
Passage Three
The frst line reads：“She sits on the bed with a helpless expression.What is your name？Auguste. Last name？Auguste.What is your husband’s name？Auguste，I think.”The 32 pages of medical records that follow are the oldest medical description of Alzheimer’s disease.Psychiatrist Konrad Maurer and his colleagues at Johann Wolfgan Goethe University in Frankfurt found the fle in their hospital’s archive， where it had been missing for nearly 90 years，and published excerpts from it last May in The Lancet. The notes，in a cramped，archaic German script，were written by Alois Alzheimer—the physician who frst described the disease.
His patient，Auguste D，was a 51-year-old woman who had suffered fts of paranoid jealousy and memory lapses so disturbing that her family fnally brought her to a local hospital known as the Castle of the Insane.Over the next four years Alzheimer tracked her condition.Upon her death he examined her brain tissue and found the distinctive lesion that are now hallmark of the disease.
Today Alzheimer’s afflicts some 4 million Americans.Although it still cannot be cured，or even treated very well，several recent studies hint that some treatments—from estrogen to vitamin E to anti-infammatory drugs—can reduce either the risk of developing the disorder or its symptoms.And more is being learned about its distinctive pathology.This past year，for instance，researchers discovered a new kind of lesion in Alzheimer’s patients.A genetic study also pinpointed a mutation that is present in some 60 percent of them—a mutation in the DNA of mitochondria，the energy-producing organelles of the cells.
But nearly a century ago，it was Alois Alzheimer who frst described the disease and in so doing became one of the frst physicians to offer a biological basis for a psychiatric condition.Finding the fle， Maurer says，“is like holding history in your hands”.
71.Obviously，the discovery of the missing fle of Auguste D____.
A.adds credit to Alois Alzheimer
B.sheds doubt on the frst description of Alzheimer’s
C.presents a big challenge to the medical community
D.has a great impact on the development of a cure for Alzheimer’s
72.The anatomical characteristics of Alzheimer’s____.
A.can be found in the missing fle B.could have been confrmed decades ago
C.are wrongly described in the missing fle D.even puzzle the medical community today
73.The fndings of the research on Alzheimer’s____.
A.sound encouraging B.took more time than expected
C.were ascribed to the missing fle D.will bring about a cure in no time
74.When he says that fnding the fle is like holding history in your hands，Maurer means.
A.his assurance of the historical fnding B.his further studies on Alzheimer’s
C.the beauty of the medical history D.the importance of imagination
75.Which of the following can best be the title for the passage？
A.The Physician Who First Described Alzheimer’s
B.The Recent Studies on Alzheimer’s
C.The Missing File of Auguste D
D.The History of Psychiatrics
Passage Four
Dry-cleaning machines that use liquid carbon dioxide as a solvent will go on sale in the US next year—thanks to chemists in North Carolina who have developed CO2-soluble detergents.Dry-cleaners will lose their characteristic smell，and the new process will cut the amount of toxic waste produced in cleaning clothes.
Joseph DeSimone，a chemist at the University of North Carolina，Chapel Hill，says liquid CO2 is an ideal solvent because after cleaning，the CO2 can be evaporated off，collected，liquefed and reused.
The problem in developing the process，says DeSimone，has been that CO2 by itself is not a good solvent.However，he points out that not much dissolves in water without the help of detergents，yet water is the most common solvent.What CO2 needed，he thought，was the right detergent.
Detergent molecules such as those in washing-up liquid have two chemically distinct ends：one has a liking for water，the other sticks to dirt.Normal detergents do not dissolve in liquid CO2，so DeSimone created three CO2-soluble detergents.One end of the detergents has a fuorocarbon group，which makes them soluble in CO2.The other end is soluble in water，oil or silicone，depending on the type of dirt being removed.The person doing the dry-cleaning has to decide which of the detergents is best for the job.
DeSimone’s company，MiCell，will start selling liquid CO2 dry-cleaning machines next year.They operate at room temperature at a pressure“about ten times the pressure of a bicycle tyre”，according to a spokesman for MiCell.
Most dry-cleaners currently use chlorinated hydrocarbons such as perchloroethylene.But the U.S.Environmental Protection Agency（EPA）is clamping down on the toxic waste emission this produces. After cleaning with the new machines，the liquid CO2 is evaporated and collected for reuse，leaving a residue of detergent and dirt.
Brad Lienhart，president of MiCell，says that cutting waste and pollution is the company’s strongest selling point.“Dry-cleaner owners are saying‘get this burden off my back’，”he says.He hopes to sell a hundred machines in the first year of business.About 15，000 conventional dry-cleaning machines are sold around the world every year.Buster Bell，who owns Bell Laundry and Dry Cleaning in South Carolina，says the MiCell technology looks competitive，and he likes the reduced environmental impact.“You really don’t know what is coming from the EPA，”he says.
76.The passage begins with____.
A.a commercial advertisement B.a horrible warning
C.a sale promotion D.good news
77.What is the liquid CO2 for？
A.Better cleaning clothes.
B.Helping recycle dry cleaners.
C.Dissolving the toxic waste from dry cleaning.
D.Reducing the toxic emission from dry cleaning.
78.The right detergent for CO2____.
A.makes dry cleaning easy B.must be chemically soluble
C.is chemically of two purposes D.means a right person for dry-cleaning
79.When they are saying“get this burden off my back”，the dry-cleaner owners refer to____.
A.the competition in the business of dry cleaning
B.the pressure from EPA
C.their potential proft
D.their selling point
80.What is the strongest selling point of the MiCell technology according to Lienhart？
A.It will promote dry-cleaning business. B.It is environment-friendly.
C.It costs less in the market. D.A1l of the above.
Passage Five
The alarm on our household computer terminal rings and wakes me up.My husband simply stirs and goes back to sleep.I transfer today’s information onto the personal data card I carry with me everywhere and scan today’s readings.Values are given as to the number of liters of water I can use，the amount of coal-generated electricity I have allocated and how many“enviro-credits”I have learned.
I am free to use the water and electricity as I chose，however I notice that the ration of electricity is decreasing every day.Of course，this will not be a problem when we have earned enough enviro-credits to buy another solar panel.Enviro-credits are earned by buying goods with limited of no packaging，minimizing the amount of garbage thrown out by fnancially supporting“environtechnology”.Before cars were phased out due to unpopularity，credits could be gained by using public transport.
I notice all extra passage added to the readings.At last I have been given permission to have a child.Almost instantaneously a package arrives with a label on it—“Anti-sterilization Unit”.Inside there are instructions and a small device that looks like a cross between a pistol and a syringe.Eagerly I follow the instructions.The procedure is painless and I don’t know if I am imagining it but I seem to feel the effects at once.
Shaking my husband awake，I tell him the good news.I want to get started baby-making right now. “You’ve been on the waiting list for 37 years，”he says，“Can’t you wait until I’ve woken up properly？”
I decide that I probably don’t have much choice and wander downstairs.I am feeling very privileged to have the opportunity to create a new life.It is saddening，however，when I realize that，because of strict population controls，this new life will be replacing an old one.
I decide to ring my mother and tell her the good news.When she answers the phone she is crying.She has received word that my grandmother has failed her latest health check and will be euthanized next week.
For some reason，I don’t feel like creating that new life anymore.
81.Based on today’s data，the wife will____.
A.use up all the envirocredits she earned
B.make arrangements with her husband for the day
C.be allowed to use a certain amount of water and electricity
D.do as required to generate enough water and electricity for the day
82.According to the passage，enviro-credits go to those who____.
A.recycle their garbage at home B.limit themselves to solar energy
C.push environtechnology forward D.do something environment-friendly
83.The effects the wife is feeling at once following the instructions refers to____.
A.the desire to make a baby B.the permission to make a baby
C.the device to help her make a baby D.the consequences of making a baby
84.The good news for the wife changes into bad news because____.
A.she has to wait for another 37 years
B.to create a new life is to replace an old one
C.population is strictly controlled in the country
D.today she is not healthy enough to make a baby
85.What is the passage？
A.It is a scenario. B.It is a true story.
C.It is a piece of news. D.It is a scientifc report.
Passage Six
Just because you’re better educated doesn’t mean that you’re any more rational than everyone else，no matter how hard you may try to give that impression.
Take the selection of lottery numbers.A survey in Florida described at this year’s annual meeting of the American Association for the Advancement of Science shows that better educated people try to use random number systems to pick their lottery numbers.
Despite the apparent logic of choosing random numbers，however，their chances of winning are no better than those of ordinary folk who use birthdays，anniversaries and other“lucky”dates.Nor are they better off than those who draw on omens and intuitions，picking numbers seen on car number-plates and in dreams.But no doubt they feel a lot more rational.
That appearance of“rationality”may be a dangerous thing.Scientists are not immune to subtle and subjective infuences on their judgments.Take the data from a survey of the public and member of the British Society Of Toxicology discussed at the same meeting.
The survey showed that most people agree with the view that animals can be used to help predict how human will react，to chemicals，and that if a chemical causes cancer in an animal，we can be “reasonably sure”it will cause cancer in humans.The toxicologists，however，are more circumspect.They accept the frst statement but less likely to agree that if a chemical causes cancer in an animal，it will do so in a human.
Can this difference be attributed to their expertise？Perhaps.But consider the considerable variation among toxicologists：those who were young，female，working in academia rather than industry or who felt that technology is not always used for the good of all，were more likely to agree that what causes cancer in an animal will cause cancer in a human.
Maybe we need to think more about how who we are affects our“rational”decisions.
86.According to the Florida-based survey，those who are better educated feel a lot more rational about the way they____.
A.look at the world
B.use logic in doing science
C.choose their lottery numbers
D.use numbers professionally and personally
87.Actually，the selection of random numbers，____.
A.does not work any better than the use of omens and intuitions
B.stands more chance of winning a lottery in the United States
C.is wrongly appreciated by rational people
D.is widely practiced in lottery
88.What are the survey data suggesting in the passage？
A.We are living in the age of rationality.
B.Nobody can be trusted in terms of truth.
C.Humans and animals do not react to chemicals in the same way.
D.The sense of rationality cannot avoid being subjectively infuenced.
89.What the author is trying to say in the passage____.
A.can be further illustrated by the opinion among toxicologists
B.is acceptable to those young and female toxicologists
C.is rational enough to accept in the world of science
D.has much to do with his own experience
90.Which of the following can be the best title for the passage？
A.A Very Comforting Illusion
B.A Rational Approach to Lottery
C.A Survey on Education and Rationality
D.A Difference between Scientists and Others
试卷二（Paper Two）
Part ⅤWriting（20%）
Directions：In this part there is an essay in Chinese.Read it carefully and then write a summary of 200 words in English on the ANSWER SHEET.Make sure that your summary covers the major points of the essay.
水果是否可吃可不吃
水果含有人体必需而又不能自身合成的矿物质，具有强抗氧化作用、防止细胞衰老的维生素以及可以明显降低血液中胆固醇浓度的可溶性纤维等，对人体健康十分有益。但中国人特别是男性，经常吃水果的比例很低。20世纪80年代，我在美国分析了美国对100万人进行十年追踪研究的资料，发现不吃或很少吃水果的人群，肺癌死亡率为吃水果人群的1.75倍。而且从45岁到74岁的每个5岁年龄组均表现出类似的结果，说明这种因果关系非常可靠。美国有句谚语：“一天一个苹果，不用看医生。”说明他们很早就总结出了水果对疾病的预防作用。世界卫生组织近年来提出了“天天五蔬果”的口号。其含义是，为保障健康，最好每天吃够五种蔬菜和五种水果。近年来美国哈佛大学的一些研究表明，多进食水果和蔬菜还可降低中风和冠心病的发病危险。
那么，到底水果中的什么成分起到了这样的作用？是不是维生素？服用市售维生素制剂是否可起到相同的作用？我又进一步分析了肺癌死亡与服用维生素制剂的关系。结果发现，经常服用维生素并不能起到类似的保护作用。再专门分析重度吸烟者肺癌死亡率与进食水果和服用维生素制剂的关系。发现水果仍然起到保护作用，而维生素却没有。该分析研究的结论是，人工合成的维生素不能替代水果对肺癌死亡的预防作用，后来的一些研究也得出了同样的结论。对此，营养免疫学家的解释是：天然植物中的维生素并不是单独起作用，而是与其他维生素和营养素相互联合一起工作。一种维生素补充的过多或不足，均会影响和削弱其他营养素或维生素的作用。由于化学合成的维生素是与其他维生素和营养素分离的，复方的各成分间的比例也与天然的不尽相同，所以它们不能产生与天然物质中所含的维生素一样的功效。有些国外的专家把这种现象戏称为“人造的不如神造的”。另外，蔬菜水果中还可能含有些尚未被人类认识的生理活性物质。目前，天然食物的抗氧化作用已成为一个重要的研究领域，各国营养学家正在进行研究开发。研究已证实，有些蔬菜水果具有强抗氧化作用，如大蒜、胡萝卜、柿子、柑橘、猕猴桃等能提高体内超氧化物岐（质）化酶（SOD）的活性，起到延缓衰老的作用。
综上所述，在日常生活中，水果应作为每日膳食的重要组成部分，绝不是可有可无的东西。对一般人群来说，维生素制剂绝不能也不应当代替日常对水果、蔬菜的进食。另外，过多地服用维生素制剂还可能导致一些副作用，有的甚至非常严重。如服用过量维生素D会导致软组织钙化，对肾脏和心血管系统造成损伤；长期服用维生素E易导致血栓等。在病态情况下，由于体内某些维生素的大量消耗或吸收合成转化不良，打破了其正常平衡，则必须适当补给。如发热、手术、患心肌梗死等疾病时需补充维生素C；肝肾功能不良时需补充维生素D等。但这些均需在医生的指导下进行。