《研究生英语精读教程》(第三版上)

研究生英语精读教程答案【篇一：研究生英语精读教程人大版(第三版上)-答案1-4章】e你认为自己是什么样的人，那你就是什么样的人如果你改变想法——从悲观变为乐观——你就可以改变自己的生活卡勒普-撒弗兰[ 1 ] 你看酒杯是半杯有酒而不是半杯空着的吗?你的眼睛是盯着炸面圈，而不是它中间的孔吗? 当研究者们自细观察积极思维的作用时，这些陈辞滥调突然问都成了科学问题。

[ 5 ] 公司受到了触动，便雇用了100名虽未通过标准化企业测试但在态度乐观一项得分很高的人。

这些本来可能根本不会被雇用的人售出的保险额高出推销员的平均额10％。

[ 6 ] 他们是如何做的呢？据塞利格曼说，乐观主义者成功的秘诀就在于他的“解释方式”。

出了问题之后，悲观主义者倾向于自责。

他说：“我不善于做这种事，我总是失败。

”乐观主义者则寻找漏洞，他责怪天气、抱怨电话线路、或者甚至怪罪别人。

他认为，是那个客户当时情绪不好。

当一切顺利时，乐观主义者居功自傲而悲观主义者只把成功视为侥幸。

[ 8 ] 无论是消极还是积极，都是一种自我实现的预言。

安德森说：如果人们感到没有希望，他们就不会费事去获得成功所需的技能。

”[ 9 ] 据安德森看来，有无控制感是成功的试金石。

乐观主义者能够掌握自己的命运。

如果事情不顺利，他立刻做出反应，寻找解决办法，制定新的行动计划，并且主动寻求指点。

悲观者刚感到自己只能由命运摆布，行动拖拉。

既然认为毫无办法．他便不去寻求指点． [11] 乐观态度不会使不治之症痊愈，却有可能预防疚病。

在一项长期研究中，研究人员跟踪观察了一组哈佛大学毕业生的健康史。

所有这些人部是班上的好学生，并且健康状况良好。

他们之中有的是积极思考者，有的是消极思考者。

20年后，悲观者中患有中年常见病一高血压、糖尿病、心脏病一的人数要比乐观者多。

[ 13 ] 在多数人身上，乐观主义和悲观主义兼而有之，但总是更倾向于其中之一。

塞利格曼说，这是一种所谓早在“母亲膝下”就开始形成的思维模式，来自千万次警告或鼓励，积极的或消极的话语。

Unit SixTwo Truths to Live ByHold fast, and let go:understand this paradox*, and you standat thevery gate of wisdomAlexander M. Schindler[ 1 ] The art of living is to know when to hold fast and when to let go. For life is a paradox: it enjoins* us to cling to* its many gifts even while it ordains* their eventual relinquishment*The rabbis* of old put it this way: "A man comes to this world with his fist clenched*, but when he dies, his hand is open."[1] 生活的秘诀在于懂得何时抓紧，何时放松。

因为人生就是一对矛盾：它既令我们抓紧人生的多种赐与，同时它又要我们到头来把这些赐与放弃。

老一辈犹太学者是这样说的：“ 一个人握紧拳头来到这个世界，但他却是松开手掌离开这世界的。

”[ 2 ] Surely we ought to hold fast to life, for it is wondrous*, and full of a beauty that breaks through* every pore* of God's own earth. We know that this is so, but all too often we recognize this truth only in our backward glance when we remember what it was and then suddenly realize that it is no more.[2] 毫无疑问，我们应该牢牢抓住生命，因为它奇妙，它有一种在上帝创造的世界里无孔不入、无处不在的美。

研究生英语精读教程（第三版上）Unit 1-5Unit 11. Those who believed their religious leader’s prophecy that the end of the world would come soon went into a panic.A. announcementB. forecastC. predictionD. declaration2. It became obvious when the boy floundered through the recitation in class today that he had not taken the trouble to do his homework.A. meditatedB. falteredC. contemplatedD. staggered3. The teacher told the students that they should avoid using clichés in their composition.A. popular proverbsB. well-known storiesC. famous quotationsD. trite expressions4. After listening to the same old moral lesson all these years, the villagers became almost immune to it.A. insensitive toB. fed up withC. familiar withD. accustomed to5. I can't claim credit for her English proficiency; after all, she only came to my class this semester.A. ask for moneyB. expect paymentC. say that I deserve praiseD. declare that I am grateful6. Believe it or not, this popular novel now you see on every shelf was censored only a few years ago.A. officially examined and bannedB. despised by the general publicC. sold out soon after its publicationD. condemned by the critics7.The party leader regards the result of the election as a personal triumph.A. victoryB. celebrationC. satisfactionD. propaganda8.The immigration officer scrutinized his passport before he was allowed to leave.A. StampedB. examinedC. returnedD. issued9. He suffered a long period of depression before his first suicide attempt.A. InoculationB. hypertensionC. ailmentsD. dejection10. He was never able to enjoy the metropolitan delights of cinemas and theatres.A. artisticB. modernC. urbanD. various11. He quickly _____ behind the building to avoid being hurt by the stones thrown in his direction.A. eludedB. evadedC. escapedD. dodged12. His dislike of the course may prove to be a _____ barrier he cannot overcome.A. BiologicalB. ideologicalC. spiritualD. psychological13. As the Cup Final was drawing closer, the injury of the best player was a _____ for the whole team.A. misdemeanourB. mistrustC. misfortuneD. mischief14. The best solution to the problem can only be found by a process of trial and _____.A. errorB. mistakeC. successD. experiment15. He thought that he might be able to avoid paying some of his taxes by taking advantage of the ______ in the law.A. circlesB. loopholesC. exceptionsD. misunderstanding16. When he lived in that remote place, radio was the only means he had to keep _____ of current events in the country.A. accountB. traceD. track17. ______ what is generally believed, the adjustment to this kind of work is quite easy.A. Contrary toB. Contrast withC. Controversial ofD. Contradictory to18. The flashing red light served as a ______ of danger ahead.A. predictorB. cautionC. precautionD. prevention19. Their confidence in him was greatly ______ by his prolonged hesitation before taking any action.A. appreciatedB. confirmedC. underminedD. cherished20. Your headache is likely to ______ if its real cause is not identified and proper treatment administered accordingly.A. cureB. recoverC. recurD. releaseUnit 21. After his father died, Bill took on the management of the factory.A. gotB. undertookC. organizedD. held2. Those students who have access to his esoteric discussions were impressed by the scope of his thinking.A. known by fewB. known to allC. very livelyD. quite popular3. The music of the radio distracted me from my reading.A. engrossedB. confusedC. refrainD. diverted4. Abraham Lincoln was quintessential American patriot.B. famousC. typicalD. revered5. Every now and then, the speaker interjected some witty remark.A. rejectedB. criticizedC. insertedD. jeered6. Why do you get angry over such trivial matters?A. of great worthB. of great benefitC. of little worthD. of little help7. The youngest boy was laughed at for his naive remarks.A. innocentB. wittyC. amusingD. foolish8. The lady rumpled her skirt by sitting on the seat while flying.A. disorderedB. disarrangedC. creasedD. crashed9. Thousands of people are needlessly slaughtered in road accidents in his country each year.A. woundedB. killedC. injuredD. crushed10. I bought this cloth cheap because there is a small defect in it.A. spotB. dotC. flawD. point11. Your job is not to make decisions but to _____ the decisions we make.A. completeB. accomplishC. implementD. affect12. Would you _____ him among th e world’s great statesmen?A. rankB. callC. nameD. hail13. Understanding is one of the most important _____ of a successful marriage.A. ingredientsB. standardsC. keysD. methods14. There are _____ of poison in the dead man’s blood.A. piecesB. tracesC. slicesD. lots15. He had been ill for months, and we were disturbed by his _____ complexion.A. fairB. sallowC. darkD. white16. A witness in court is _____ to tell the truth.A. temptedB. obligatedC. urgedD. praised17. A _____ swelling or tumour can usually be cured.A. malignantB. benignC. smallD. mild18. It is better to _____ on the side of mercy.A. errB. addC. workD. offer19. He has a very _____ address; he lives in the best part of town.A. wealthyB. comfortableC. prestigiousD. Accessible20. We all listened to the priest _____ the psalm.A. intoningB. utteringC. speakingD. deliveringUnit 31. High rate of unemployment and violence are deplored by many people.A. condemnedB. convincedC. declaredD. perpetuated2. They are planning to embark on a new business undertaking.A. go forB. go withC. go intoD. go on3. In the Middle Ages, many people in Europe suffered persecution for their religious beliefs.A. treatmentB. punishmentC. disillusionD. execution4. We couldn’t induce the old lady to travel by air.A. driveB. convinceC. forceD. suggest5. He went into a coma because of serious loss of blood.A. bad coughB. whitenessC. tremblingD. state of profound insensibility6. The ethics of his decision are doubtful.A. raceB. aestheticsC. moralsD. cause7. The patients tax the doctor's patience by asking him so many silly questions.A. pestB. are a strain onC. injureD. destroy8. They broke up the alliance.A. brought to an endB. dispersedC. stopped to enter intoD. changed for the worse9. The boys were summoned in turn to see the examiner.A. separatelyB. occasionallyC. allD. in succession10.They traveled all over the country, regardless of expense.A. unkind toB. paying no attention toC. forgettingD. concerned with11.The story was so funny that we were all in __________.A. excitementB. convulsionsC. emotionD. fixation12.Gluttony is just as much a __________ as drunkenness.A. viceB. vicinityC. viciousnessD. vicissitude13.Each room is decorated with a lamp ________ from the ceiling.A. droppedB. pulledC. suspendedD. fallen14.My first meeting with her often __________ to my memory.A. fellsB. recallsC. refreshesD. recurs15.He writes like a(n) __________: there are mistakes in every sentence.A. pupilB. illiterateC. teenagerD. school boy16.The goal is not yet ____________.A. to gainB. to sustainC. to restrainD. to attain17.It was reported that during the bombing, many people were killed or wounded by _____________.A. flowB. blastC. currentD. stream18.She learnt to swim at once - she seemed totally without _________ of the water.A. panicB. fearD. terribleness19. We raised a we must pay off it this year ______.A. creditB. good sumC. loanD. mortgage20. Some children complain that their parents ______ at them all day.A. blameB. scoldC. nagD. cryUnit 4B. great regretC. great despairD. great disappointment2. I have nothing but disdain for such a person.A. respectB. hatred3. The grass was interspersed with beds of flowers.A. scatteredB. spread4. I am sure disease must propagate in such unsanitary and crowded areas.C. promoteD. generate5. There was a meager attendance at the council meeting.B. enoughC. ampleD. haughty6. The end of 1921 found the capitalist offensive against the workers in full swing.A. negotiationB. punishmentB. refuseC. acceptD. take8. John was confined to bed for a week with his cold.C. tied toD. shut on9. We three were the sole survivors in the traffic accident.A. luckyB. fortunate10. I slept through her dull speech.C. fascinatingD. imaginative11. I have been in _________ with him about the matter.A. lettersB. dealings12. I could hear only __________ of their conversation.A. piecesD. portions13. The old lady ______ the sweet-smelling flowers into a garland.C. curvedD. twistedB. prudentC. shrewdD. rude15. Most bacteria grow best in a slightly acid ______.A. areaB. place16. Everyone knows that the firefly is a _____ insect.A. firingD. glowing17. Sports, and not learning, seem to ______ in that school. A. appearD. lead18. Each chess player will have five minutes to ______ his next move. A. makeB. have19. This time they really ______ better results.C. wishedD. wished toB. A wordC. WordsD. The wordUnit 51. His beautiful writing is akin to drawing.A. asB. from2. His knowledge on the subject seems to be on a par with my own. A. different fromC. related toD. in accordance with3. Tom and Mary were married a week after they met and soon found themselves at odds aboutB. on strikeC. in questionD. on purpose4. The inventor was vilified in yesterday's newspaper.C. praisedD. criticized5. The Mississippi flood of 1973 was a major catastrophe in which a great many lives were lost.C. changeD. threat6. She almost yielded to an unexpected impulse to dance in the street.C. good ideaD. fancy thought7. Mr. Green posed as a rich man though he owed more than he owned.A. workedB. looked8. They feared the plague and regarded it as a deadly scourge.B. IllnessC. troubleD. ailment9. Some people have a bias against foreigners.B. dislikeC. hatredD. favour10. Your stay abroad will give you ample opportunities to learn a new language.A. goodB. suitableB. surprisingC. fastD. unexpected12. Since the club owed $15 and had only $10 in the treasury, there was a ______ of $5.C. differenceD. surplus13. The oil lamp ______ softly on the table.A. glowedD. sounded14. It ______ with you to decide.A. talksD. indicates15. He ______ among the best heavyweight boxers of the past fifty years.A. projectsB. shows16. The constant turmoil in the office proved that he was an ______ administrator.C. experiencedD. active17. The mother tried to ______ her son’s interest in music by taking him to concerts when he was young.A. giveD. cause18. No matter how you read it, this sentence doesn’t make any __.A. meaningB. sound19. I tried to find my keys but I was ______ by my thick gloves.C. annoyedD. upsetB. interestedC. amusedD. disturbed。

研究生英语系列教材研究生英语精读教程教师参考书（第三版·上）ContentsUnit OneText: You Are What You Think (1)Supplementary Reading (10)Unit TwoText: Cancer & Chemicals (11)Supplementary Reading (18)Unit ThreeText: Rats and Men (19)Supplementary Reading (27)Unit FourText: Einstein’s Painful Romance (29)Supplementary Reading (35)Unit FiveText: The End Is Not at Hand (37)Supplementary Reading (44)Unit SixText: Two Truths to Live By (47)Supplementary Reading (58)Mini-Test Ⅰ (59)Unit SevenText: Good Taste, Bad Taste (61)研究生英语精读教程教师参考书（第三版/上）Supplementary Reading (70)Unit EightText: I Have a Dream (73)Supplementary Reading (80)Unit NineText: This Was My Mother (81)Supplementary Reading (91)Unit TenText: Digital Revolution: How the Korean Group Becamea Global Champion (93)SupplementaryReading (100)Unit ElevenText: In Search of the Real Google (101)Supplementary Reading (118)Unit TwelveText: A Red Light for Scofflaws (119)Supplementary Reading (129)Mini-Test Ⅱ (131)►Text:You Are What You ThinkClaipe SafranLanguage Points1. Para. [2]: mental illsWhen used as a noun, “ill” means “anything causing harm, trouble,wrong,un happiness, etc., specifically: a) an evil or misfortune; b) a disease”.Its synonyms in this lesson: disease (Para.10), ailments(Para.11), illness (Para.11)Other synonyms: sickness, ailing, infirmity, indisposition, complaint, disorder, malady, distemper2. Para. [7]: When they failed on the first call or two ...When the first few people they phoned refused to donate blood ...3. Para. [8]: self-fulfilling prophecya prediction brought to fulfilment chiefly as an effect of having been expected or predicted4. Para. [9]: A sense of control ... is the litmus test for success.Whether one feels in control of the situation will determine if one succeedsin the end.5. Para. [10]: ... think they are better than the facts would justify ...overestimate themselves; regard themselves as better than they really are 6. Para. [13]: at one’s m other’s kneewhen one is a small child研究生英语精读教程教师参考书（第三版/上）Word Study1. donate v.donation n.donator n.①He donated all his savings to the village school.②They have donated to the Red Cross.③The van was donated to us by a local firm.④The new library has received a generous donation of 200 rare books from its favourite patron.⑤He made a donation of $1,000 to the children’s hospital.⑥The Famine Relief Fund has received 500 yuan in cash from an anonymous donator.2. recur v.recurring adj.recurrent adj.recurrence n.①He is more concerned about those problems which recur periodically.②If you divide 10 by 3, the result will be a recurring decimal.③Lack of confidence in himself will be a recurring problem for him in the future.④The patient complained of a recurrent headache.⑤He was aware of the possibility of recurrence of his illness.⑥His words of encouragement recurred to my mind whenever I was in low spirits.3. immune (to/against/from) adj.immunity n.immunize v.immunology n. study of resistance to infection①He seems to be immune to flattery.②We are immune from smallpox as the result of vaccination.③The child has received immunity to a variety of infections.Unit One④He was given immunity from taxation on the ground that he had been seriously injured.⑤Ambassadors enjoy diplomatic immunity in the countries in which they are stationed.⑥Everyone who is going abroad will need to be immunized againsttyphoid.⑦The government is going to spend more money on its immunizationprogram.⑧He has devoted all his life to immunology.4. caution n. & v.cautious adj.①You must exercise extreme caution when you cross this street.②The police gave him a caution for speeding.③The policeman cautioned the motorist about his speed.④They cautioned him about danger.⑤His teacher cautioned him that he might fail his exam.⑥If I had been less cautious, I might have made greater progress.⑦They are very cautious of/about giving offence.⑧He walked cautiously in this unknown territory.5. triumph n. & v.triumphant adj.①The conquest of outer space is one of the greatest triumphs of modernscience.②His life was a triumph over ill health.③Though he had beaten his opponent in the election, they could detect notriumph in his eye.④Grinning broadly, he held up the prize in triumph.⑤Justice triumphs in the end.⑥He triumphed over many difficulties.⑦Her triumphant smile told me how proud she was of her success.⑧Having succeeded at his first attempt, the boy looked at me triumphantly.研究生英语精读教程教师参考书（第三版/上）参考译文你认为自己是什么样的人，那你就是什么样的人如果你改变想法——从悲观变为乐观——你就可以改变自己的生活卡勒普·撒弗兰[1] 你看酒杯是半杯有酒而不是半杯空着的吗？你的眼睛是盯着炸面圈，而不是它中间的孔吗? 当研究者们仔细观察积极思维的作用时，这些陈词滥调突然间都成了科学问题。

Unit OneText:You Are What You ThinkAnd if you change your mind-from pessimism to optimism-you can change your lifeClaipe Safran[1] Do you see the glass as half full rather than half empty? Do you keep your eye upon the doughnut, not upon the hole? Suddenly these clichés are scientific questions, as researchers scrutinize the power of positive thinking.[2] A fast-growing body of research—104 studies so far, involving some 15,000 people—is proving that optimism can help you to be happier, healthier and more successful. Pessimism leads, by contrast, to hopelessness, sickness and failure, and is linked to depression, loneliness and painful shyness. "If we could teach people to think more positively," says psychologist Craig A. Anderson of Rice University①in Houston②，"it would be like inoculating them against these mental ills."[3] "Your abilities count," explains psychologist Michael F. Scheier of Carnegie Mellon University③in Pittsburgh④, "butthe belief that you can succeed affects whether or not you will." In part , that's because optimists and pessimists deal with the same challenges and disappointments in very different ways. [4] Take, for example, your job. In a major study, psychologist Martin E. P. Seligman of the University of Pennsylvania⑤ and colleague Peter Schulman surveyed sales representatives at the Metropolitan Life Insurance Co. They found that the positive-thinkers among longtime representatives sold 37-percent more insurance than did the negative-thinkers. Of newly hired representatives, optimists sold 20-percent more. [5] Impressed, the company hired 100 people who had failed the standard industry test⑥ but had scored high on optimism. These people, who might never have been hired, sold 10 percent more insurance than did the average representative.[ 6 ] How did they do it? The secret to an optimist's success, according to Seligman, is in his "explanatory style". When things go wrong the pessimist tends to blame himself. "I'm no good at this, " he says, "I always fail." The optimist looks for loopholes. He blames the weather, the phone connection, even the other person. That customer was in a bad mood, he thinks. When things go right, the optimist takes credit while the pessimist sees success as a fluke.[ 7 ] Craig Anderson had a group of students phone strangers and ask them to donate blood to the Red Cross⑦. When they failed on the first call or two, pessimists said, "I can't do this." Optimists told themselves, "I need to try a different approach." [ 8 ] Negative or positive, it was a self-fulfilling prophecy. "If people feel hopeless, "says Anderson, "they don't bother to acquire the skills they need to succeed."[9] A sense of control, according to Anderson, is the litmus test⑧ for success. The optimist feels in control of his own life. If things are going badly, he acts quickly, looking for solutions, forming a new plan of action, and reaching out for advice. The pessimist feels like fate's plaything and moves slowly. He doesn't seek advice, since he assumes nothing can be done.[ 10 ] Optimists may think they are better than the facts would justify—and sometimes that's what keeps them alive. Dr. Sandra Levy of the Pittsburgh Cancer Institute studied women with advanced breast cancer. For the women who were generally optimistic, there was a longer disease-free interval, the best predictor of survival. In a pilot study of women in the early stages of breast cancer, Dr. Levy found the disease recurred sooner among the pessimists.[ 11 ] Optimism won't cure the incurable, but it may preventillness. In a long term study, researchers examined the health histories of a group of Harvard graduates, all of whom were in the top half of their class and in fine physical condition. Yet some were positive thinkers, and some negative. Twenty years later, there were more middle-age diseases—hypertension, diabetes, heart ailments —among the pessimists than the optimists.[ 12 ] Many studies suggest that the pessimist's feeling of helplessness undermines the body's natural defenses, the immune system. Dr. Christopher Peterson of the University of Michigan⑨ has found that the pessimist doesn't take good care of himself. Feeling passive and unable to dodge life's blows, he expects ill health and other misfortunes, no matter what he does. He munches on junk food⑩，avoids exercise, ignores the doctor, has another drink.[ 13 ] Most people are a mix of optimism and pessimism, but are inclined in one direction or the other. It is a pattern of thinking learned “at your mother‘s knee”，says Seligman. It grows out of thousands of cautions or encouragements, negative statements or positive ones. Too many “don’ts” and warnings of danger can make a child feel incompetent, fearful—and pessimistic.[ 14 ] As they grow, children experience small triumphs, such as learning to tie shoelaces. Parents can help turn these successes into a sense of control, and that breeds optimism. [ 15 ] Pessimism is a hard habit to break—but it can be done. In a series of landmark studies, Dr. Carol Dweck11of the University of Illinois12has been working with children in the early grades of school. As she helps floundering students to change the explanations for their failures—from "I must be dumb" to "I didn't study hard enough“—their academic performance improves.[ 16 ] Pittsburgh's Dr. Levy wondered if turning patients into optimists would lengthen their lives. In a pilot study, two groups of colon-cancer patients were given the same medical treatment, but some were also given psychological help to encourage optimism. Results showed that this worked. Now a major study is planned to determine whether this psychological change can alter the course of the disease.[ 17 ] So, if you're a pessimist, there's reason for optimism. You can change. Here's how, says Steve Hollon, a psychologist at Vanderbilt University13:[ 18 ] 1. Pay careful attention to your thoughts when bad things happen. Write down the first thing that comes to mind,unedited and uncensored[ 19 ] 2. Now try an experiment. Do something that's contrary to any negative reactions. Let's say something has gone wrong at work. Do you think, I hate my job, but I could never get a better one?Act as if that weren't so. Send out resumés. Go to interviews. Look into training and check job leads[ 20 ] 3. Keep track of what happens. Were your first thoughts right or wrong? "If your thoughts are holding you back, change them," says Hollon. "It's trial and error, no guarantees, but give yourself a chance."[ 21 ] Positive thinking leads to positive action, and reaction. What you expect from the world, the evidence suggests, is what you're likely to get..。

Unit twoText:Cancer & Chemicals-Are We Going Too Far?Marla ConeLast year, California governor George Deukmejian called together many of the state's best scientific minds to begin implementing Proposition 65, the state's Safe Drinking Water and Toxic Enforcement Act. This new law bans industries from discharging chemical suspected of causing cancer (carcinogens) or birth defects into water supplies. Some claim it will also require warning labels on everything that might cause cancer.A day of esoteric science and incomprehensible jargon was predicted. But Bruce Ames, chairman of the department of biochemistry at the University of California at Berkeley, had plans to liven the proceedings.Walking into the room, Ames looked like the quintessential scientist: wire-rimmed bifocals, rumpled suit, tousled hair and a sallow complexion that showed he spent more time in his laboratory than in the California sunshine.As someone intoned about the mechanisms of carcinogenesis, Ames began to interject his own views."The whole world is chock-full of carcinogens," Ames declared.“A beer, with its 700 parts per billion of formaldehyde and five parts per 100 of alcohol is a thousand times more hazardous than anything in the water. If you have beer on your breath, does that mean you have to warn everyone who comes within ten feet of you?"In an era when headlines shout about the latest cancer scare, Ames has a different message: the levels of most man-made carcinogens are generally so low that any danger is trivial compared with the levels of natural carcinogens.Ames is not a quack. At age 59, he is one of the nation's most respected authorities on carcinogenesis. His resume is packed with honors, including the Charles. Mott Prize from the General Motors Cancer Research Foundation, one of the most prestigious awards in cancer research, and membership in the National Academy of Sciences.Even his critics say the Ames test —his simple, inexpensive laboratory procedure that helps determine whether a substance might cause cancer—is a remarkable achievement.But Ames slaughters sacred cows. He's taking on the environmental movement, which some have called the single most important social movement of the 20th century. In April1987, for instance, he and two colleagues, Renae Magaw and Lois Swirsky Gold, published a report in Science magazine that ranked various possible cancer risks.Based on animal tests of nearly 1,000 chemicals, the data show that daily consumption of the average peanut-butter sandwich, which contains traces of aflatoxin (a naturally occurring mold carcinogen in peanuts), is 100 times more dangerous than our daily intake of DDT from food, and that a glass of the most polluted well water in the Silicon Valley is 1,000 times less of cancer risk than a glass of wine or beer is.He's not advising people to stop consuming peanut-butter, beer and wine. What he's saying is that most cancer risks created by man are trivial compared with everyday natural risks, and it's not clear how many of these are real risks. Both types distract attention from such enormous risk factors as tobacco.Ames's cancer research began about 25 years ago over a bag of potato chips. Ames, then conducting research for the National Institutes of Health in Maryland, was reading the ingredients on the bag. It struck him that no one knew what each chemical did to human genes, and there was no easy way to find out.At that time, scientists testing for carcinogenicity had to setup time consuming and costly lab experiments on rats and mice. Armed with the knowledge that bacteria are sensitive to substances that cause mutation, and that carcinogens were likely to be mutagens, Ames developed a carcinogen test using bacteria. The Ames test was hailed as a major scientific development and is now used worldwide.One day in 1974 Ames, now teaching at Berkeley, suggested that some students test various household products. To his surprise, many common hair dyes tested positive, as did a flame retardant used in children's pajamas. Almost overnight, Ames became a hero of environmentalists when his findings led to new regulations and bans on certain chemicals.For the next decade public concern over carcinogens continued to rise. "Then," Ames says, "I started realizing something wasn't right." Too many natural substances also tested positive as carcinogens or mutagens: fruit juices, brown mustard , celery , parsley .In fact, about half of all chemicals tested by Ames—both natural and man-made—turned out to be potentially carcinogenic when given in enormous doses to rats and mice.Ames at first assumed he had erred with his test. He hadn't. His error had been making the common, but naive, assumptionthat only man-made chemicals could be dangerous. "Why assume nature is benign?" he now says.The campaign supporting California's Proposition 65 convinced Ames that he had a duty to explain this to the public. "When people said certain birth defects were caused by a part per billion of something in the water, I thought it irresponsible, " he says. "It's just playing with people's fears. You can always find a part per billion of something in the water."In testimonybefore a California senate committee, Ames noted that tap water, for instance, contains the carcinogen chloroform at about 83 ppb due to chlorination.But coffee contains two natural carcinogens at about 4,000 ppb each, while human blood averages 3,000 ppb of formaldehyde from normal metabolism.Some people assume Ames is a stooge for the chemical industry, which he is not. He does no consulting for the chemical, drug or food companies, or for law firms. And he accepts no grants from business.Environmentalists reject Ames's arguments, saying that we are obligated to keep the total exposure to carcinogens as low as possible. "Somehow he thinks there has to be a choice," says Carl Pope of the Sierra Club. "If we had to choose between TCE[a suspected cancer causing solvent] in drinking water and public education on cigarette smoking, maybe he's right. But we don't have to make a choice."Ames's reply:"You don't want every chemical company dumping their garbage out the back door. But the price you pay for living in a modern, industrial society is a few parts per billion of chemicals in the water. You can get rid of it, but at enormous cost. If you spend all your time chasing trivia, you lose sight of the important risks."。

Unit twoText:Cancer & Chemicals-Are We Going Too Far?Marla ConeLast year, California governor George Deukmejian called together many of the state's best scientific minds to begin implementing Proposition 65, the state's Safe Drinking Water and Toxic Enforcement Act. This new law bans industries from discharging chemical suspected of causing cancer (carcinogens) or birth defects into water supplies. Some claim it will also require warning labels on everything that might cause cancer.A day of esoteric science and incomprehensible jargon was predicted. But Bruce Ames, chairman of the department of biochemistry at the University of California at Berkeley, had plans to liven the proceedings.Walking into the room, Ames looked like the quintessential scientist: wire-rimmed bifocals, rumpled suit, tousled hair and a sallow complexion that showed he spent more time in his laboratory than in the California sunshine.As someone intoned about the mechanisms of carcinogenesis, Ames began to interject his own views."The whole world is chock-full of carcinogens," Ames declared.“A beer, with its 700 parts per billion of formaldehyde and five parts per 100 of alcohol is a thousand times more hazardous than anything in the water. If you have beer on your breath, does that mean you have to warn everyone who comes within ten feet of you?"In an era when headlines shout about the latest cancer scare, Ames has a different message: the levels of most man-made carcinogens are generally so low that any danger is trivial compared with the levels of natural carcinogens.Ames is not a quack. At age 59, he is one of the nation's most respected authorities on carcinogenesis. His resume is packed with honors, including the Charles. Mott Prize from the General Motors Cancer Research Foundation, one of the most prestigious awards in cancer research, and membership in the National Academy of Sciences.Even his critics say the Ames test —his simple, inexpensive laboratory procedure that helps determine whether a substance might cause cancer—is a remarkable achievement.But Ames slaughters sacred cows. He's taking on the environmental movement, which some have called the single most important social movement of the 20th century. In April1987, for instance, he and two colleagues, Renae Magaw and Lois Swirsky Gold, published a report in Science magazine that ranked various possible cancer risks.Based on animal tests of nearly 1,000 chemicals, the data show that daily consumption of the average peanut-butter sandwich, which contains traces of aflatoxin (a naturally occurring mold carcinogen in peanuts), is 100 times more dangerous than our daily intake of DDT from food, and that a glass of the most polluted well water in the Silicon Valley is 1,000 times less of cancer risk than a glass of wine or beer is.He's not advising people to stop consuming peanut-butter, beer and wine. What he's saying is that most cancer risks created by man are trivial compared with everyday natural risks, and it's not clear how many of these are real risks. Both types distract attention from such enormous risk factors as tobacco.Ames's cancer research began about 25 years ago over a bag of potato chips. Ames, then conducting research for the National Institutes of Health in Maryland, was reading the ingredients on the bag. It struck him that no one knew what each chemical did to human genes, and there was no easy way to find out.At that time, scientists testing for carcinogenicity had to setup time consuming and costly lab experiments on rats and mice. Armed with the knowledge that bacteria are sensitive to substances that cause mutation, and that carcinogens were likely to be mutagens, Ames developed a carcinogen test using bacteria. The Ames test was hailed as a major scientific development and is now used worldwide.One day in 1974 Ames, now teaching at Berkeley, suggested that some students test various household products. To his surprise, many common hair dyes tested positive, as did a flame retardant used in children's pajamas. Almost overnight, Ames became a hero of environmentalists when his findings led to new regulations and bans on certain chemicals.For the next decade public concern over carcinogens continued to rise. "Then," Ames says, "I started realizing something wasn't right." Too many natural substances also tested positive as carcinogens or mutagens: fruit juices, brown mustard , celery , parsley .In fact, about half of all chemicals tested by Ames—both natural and man-made—turned out to be potentially carcinogenic when given in enormous doses to rats and mice.Ames at first assumed he had erred with his test. He hadn't. His error had been making the common, but naive, assumptionthat only man-made chemicals could be dangerous. "Why assume nature is benign?" he now says.The campaign supporting California's Proposition 65 convinced Ames that he had a duty to explain this to the public. "When people said certain birth defects were caused by a part per billion of something in the water, I thought it irresponsible, " he says. "It's just playing with people's fears. You can always find a part per billion of something in the water."In testimonybefore a California senate committee, Ames noted that tap water, for instance, contains the carcinogen chloroform at about 83 ppb due to chlorination.But coffee contains two natural carcinogens at about 4,000 ppb each, while human blood averages 3,000 ppb of formaldehyde from normal metabolism.Some people assume Ames is a stooge for the chemical industry, which he is not. He does no consulting for the chemical, drug or food companies, or for law firms. And he accepts no grants from business.Environmentalists reject Ames's arguments, saying that we are obligated to keep the total exposure to carcinogens as low as possible. "Somehow he thinks there has to be a choice," says Carl Pope of the Sierra Club. "If we had to choose between TCE[a suspected cancer causing solvent] in drinking water and public education on cigarette smoking, maybe he's right. But we don't have to make a choice."Ames's reply:"You don't want every chemical company dumping their garbage out the back door. But the price you pay for living in a modern, industrial society is a few parts per billion of chemicals in the water. You can get rid of it, but at enormous cost. If you spend all your time chasing trivia, you lose sight of the important risks."。