2011年大学英语六级阅读理解107篇本文由dddsssrq贡献1 We can begin our discussion of "population as global issue"with what most personsmean when they discuss "the population problem":too many people on earth and a toorapid increase in the number added each year.The facts are not in dispute,It was quiteright to employ the analogy that likened demographic growth to "a long,thin powderfuse that burns steadily and haltingly until it finally reaches the charge and explodes.To understand the current situation,which is characterized by rapid increases inpopulation,it is necessary to understand the history of population trends.Rapid growthis a comparatively recent phenomenon.Looking back at the 8,000 years of demographichistory,we find that populations have been virtually stable or growing very slightlyfor most of human history.For most of our ancestors,life was hard,often nasty,andvery short.There was high fertility in most places,but this was usually balanced byhigh mortality.For most of human history,it was seldom the case that one in ten personswould live past forty,while infancy and childhood were especially risky periods.Often,societies were in clear danger of extinction because death rates could exceed theirbirthrates.Thus,the population problem throughout most of history was how to preventextinction of the human race.This pattern is important to notice.Not only does itput the current problems of demographic growth into a historical perspective,but itsuggests that the cause of rapid increase in population in recent years is not a suddenenthusiasm for more children,but an improvement in the conditions that traditionallyhave caused high mortality.Demographic history can be divided into two major periods:a time of long,slow growth which extended from about 8,000 BC.till approximately AD.1650.In the first period of some 9600 years,the population increased from some 8million to 500 million in 1650.Between 1650 and the present,the population hasincreased from 500 million to more than 4 billion.And it is estimated that by the year2000 there will be 6.2 billion people throughout the world.One way to appreciate thisdramatic difference in such abstract numbers is to reduce the time frame to somethingthat is more manageable.Between 8000BC and 1650,an average of only 50,000 personswas being added annually to the world's population each year.At present,this numberis added every six hours.The increase is about 80,000,000 persons annually.1.Whichof the following demographic growth pattern is most suitable for the long thin powderfuse analogy?A.A virtually stable or slightly decreasing period and then a suddenexplosion of population.B.A slow growth for a long time and then a period of rapid,dramatic increase.C.Too many people on earth and a few rapid increase in the numberadded each year.D.A long period when death rates exceeds birthrates and then a shortperiod with higher fertility and lower mortality.2.During the firstperiod of demographic history,societies were often in danger of extinction becauseA.only one in ten persons could live past 40.B.there was higher mortality than fertilityin most places.C.it was too dangerous to have babies due to the poor conditions.D.ourancestors had little enthusiasm for more children.3.Which statement is true aboutpopulation increase?A.There might be an increase of 2.2 billion persons from now tothe year 2000.:ABADA B.About 50,000 babies are born every six hours at present.C.Between 8000 BC and the present,the population increase is about 80,000,000 personseach year.D.The population increased faster between 8000BC and 1650 than between 1650and the present.4.The author of the passage intends to.A.warn people against thepopulation explosion in the near future.B.compare the demographic growth pattern inthe past with that after 1650.C.find out the cause for rapid increase in populationin recent years.D.present us a clear and complete picture of the demographic growth.5.The word "demographic"in the first paragraph means_.A.statistics of human.B.surroundings study.C.accumulation of human.D.development of human.2 Most of us are taught to pay attention to what is said-the words.Words do provideus with some information,but meanings are derived from so many other sources that itwould hinder our effectiveness as a partner to a relationship to rely too heavily onwords alone.Words are used to describe only a small part of the many ideas we associatewith any given message.Sometimes we can gain insight into some of those associationsif we listen for more than words.We don't always say what we mean or mean what wesay.Sometimes our words don't mean anything except "I'm letting off some steam.I don't really want you to pay close attention to what I'm saying.Just pay attentionto what I'm feeling."Mostly we mean several things at once.Aperson wanting to purchasea house says to the current owner,"This step has to be fixed before I'11 buy.Theowner says,It's been like that for years.Actually,the step hasn't been likethat for years,but the unspoken message is:I don't want to fix it.We put up withit.Why can't you?"The search for a more expansive view of meaning can be developedof examining a message in terms of who said it,when it occurred,the related conditionsor situation,and how it was said.When a message occurs can also reveal associated meaning.Let us assume two couplesdo exactly the same amount of kissing and arguing.But one couple always kisses afteran argument and the other couple always argues after a kiss.The ordering of thebehaviors may mean a great deal more than the frequency of the behavior.A friend's unusually docile behavior may only be understood by noting that it was preceded bysituations that required an abnormal amount of assertiveness.Some responses may bedirectly linked to a developing pattern of responses and defy logic.For example,a person who says "No!"toa serials of charges like“You're dumb,”“You're lazy,”and“You're dishonest,”may also say "No!"and try to justify his or her response if the next statement is"And you're good looking.We would do well to listen for how messages are presented.The words,"If sure has been nice to have you over,can be said with emphasis andexcitement or ritualistically.The phrase can be said once or repeated several times.And the meanings we associate with the phrase will change accordingly.Sometimes ifwe say something infrequently it assumes more importance:sometimes the more we saysomething the less importance it assumes.1.Effective communication is renderedpossible between two conversing partners,if.A.they use proper words to carry theirideas.B.they both speak truly of their own feelings.C.they try to understand eachother's ideas beyond words.D.they are capable of associating meaning with their words.2."I'm letting off some steam"in paragraph 1 means_.A.I'm just calling yourattention.B.I'm just kidding.C.I'm just saying the opposite.D.I'm just givingoff some sound.3.The house-owner's example shows that he actually means_.A.thestep has been like that for years.B.he doesn't think it necessary to fix the step.DBABC C.the condition of the step is only a minor fault.D.the cost involved inthe fixing should be shared.4.Some responses and behaviors may appear very illogical,but are justifiable if.A.linked to an abnormal amount of assertiveness.B.seen asone's habitual pattern of behavior.C.taken as part of an ordering sequence.D.expressedto a series of charges.5.The word "ritualistically"in the last paragraph equalssomething done_.A.without true intention.B.light-heartedly.C.in a way of ceremony.D.with less emphasis.3 A controversy erupted in the scientific community in early 1998 over the use of DNA(deoxyribonucleic acid)fingerprinting in criminal investigations.DNA fingerprintingwas introduced in 1987 as a method to identify individuals based on a pattern seen intheir DNA,the molecule of which genes are made.DNA is present in every cell of thebody except red blood cells.DNA fingerprinting has been used successfully in variousways,such as to determine paternity where it is not clear who the father of a particularchild is.However,it is in the area of criminal investigations that DNA fingerprintinghas potentially powerful and controversial uses.DNA fingerprinting and other DNAanalysis techniques have revolutionized criminal investigations by givinginvestigators powerful new tools in the attempt to trove guilt,not just establishinnocence.When used in criminal investigations,a DNA fingerprint pattern from asuspect is compared with a DNA fingerprint pattern obtained from such material as hairsor blood found at the scene of a crimeA match between the two DNA samples can be used as evidence to convict a suspect.The controversy in 1998 stemmed form a report published in December 1991 by populationgeneticists Richard C.Lewontin of Harvard University in Cambridge,Mass.,and DanielL.Hartl called into question the methods to calculate how likely it is that a matchbetween two DNA fingerprints might occur by chance alone.In particular,they arguedthat the current method cannot properly determine the likelihood that two DNA sampleswill match because they came from the same individual rather than simply from twodifferent individuals who are members of the same ethnic group.Lewontin and Hartlcalled for better surveys of DNA patterns methods are adequate.In response to theircriticisms,population geneticists Ranajit Chakraborty of the University of Texas inDallas and Kenneth K.Kidd of Yale University in New Haven,Conn.,argued that enoughdata are already available to show that the methods currently being used are adequate.In January 1998,however,the federal Bureau of Investigation and laboratories thatconduct DNA tests announced that they would collect additional DNA samples form variousethnic groups in an attempt to resolve some of these questions.And,in April,a NationalAcademy of Sciences called for strict standards and system of accreditation for DNAtesting laboratories.1.Before DNA fingerprinting is used,suspects_.A.would haveto leave their fingerprints for further investigations B.would have to submit evidencefor their innocence C.could easily escape conviction of guilt D.cold be convicted ofguilt as well2.DNA fingerprinting can be unreliable when.A.the methods used for blood-cellcalculation are not accurate B.two different individuals of the same ethnic group mayhave the same DNA fingerprinting patternC.a match is by chance left with fingerprints that happen to belong to two differentindividuals D.two different individuals leave two DNA samples.3.To geneticists likeLewontin and Hartl,the current method.A.is not so convincing as to exclude thelikelihood that two DNA samples can never come from two individuals B.is arguablebecause two individuals of the same ethnic group are likely to have the same DNA pattern.C.Is not based on adequate scientific theory of genetics D.Is theoreticallycontradictory to what they have been studying 4.The attitude of the Federal Bereau ofInvestigation shows that.A.enough data are yet to be collected form various ethnicgroups to confirm the unlikelihood of two DNA samples答案：CBABBcoming from two individual members B.enough data of DNA samples should be collectedto confirm that only DNA samples form the same person can match C.enough data are yetto be collected from various ethnic groups to determine the likelihood of two differentDNA samples coming form the same person D.additional samples from various ethnic groupsshould be collected to determine that two DNA samples are unlikely to come from the same person 5.National Academy of Sciences holds thestance that.A.DNA testing should be systematized B.Only authorized laboratoriescan conduct DNA testing C.The academy only is authorized to work out standards fortesting D.The academy has the right to accredit laboratories for DNA testing4 Racket,din clamor,noise,whatever you want to call it,unwanted sound is America's most widespread nuisance.But noise is more than just a nuisance.It constitutes areal and present danger to people's health.Day and night,at home,at work,and atplay,noise can produce serious physical and psychological stress.No one is immuneto this stress.Though we seem to adjust to noise by ignoring it,the ear,in fact,never closes and the body still responds-sometimes with extreme tension,as to astrange sound in the night.The annoyance we feel when faced with noise is the mostcommon outward symptom of the stress building up inside us.Indeed,because irritabilityis so apparent,legislators have made public annoyance the basis of many noise abatementprograms.The more subtle and more serious health hazards associated with stress causedby noise traditionally have been given much less attention.Nevertheless,when we areannoyed or made irritable by noise,we should consider these symptoms fair warning thatother thing may be happening to us,some of which may be damaging to our health.Ofmany health hazards to noise,hearing loss is the most clearly observable and measurableby health professionals.The other hazards are harder to pin down.For many of us,theremay be a risk that exposure to the stress of noise increases susceptibility to diseaseand infection.The more susceptible among us may experience noise as a complicatingfactor in heart problems and other diseases.Noise that causes annoyance andirritability in health persons may have serious consequences for these already ill inmind or body.Noise affects us throughout our lives.For example,there are indicationsof effects on the unborn child when mothers are exposed to industrial and environmentalnoise.During infancy and childhood,youngsters exposed to high noise levels may havetrouble falling asleep and obtaining necessary amounts of rest.Why,then,is therenot greater alarm about these dangers?Perhaps it is because the link between noiseand many disabilities or diseases has not yet been conclusively demonstrated.Perhapsit is because we tend to dismiss annoyance as a price to pay for living in the modernworld.It may also be because we still think of hearing loss as only an occupationalhazard.1.In Paragraph 1,the phrase "immune to"are used to mean.A.unaffectedby B.hurt by C.unlikely to be seen by D.unknown by 2.The author's attitude toward noisewould best be described as.A.unrealistic B.traditional C.concerned D.hysterical3.Which of the following best states the main idea of the passage?A.Noise is a majorproblem;most people recognize its importance.B.Although noise can be annoying,it isnot a major problem.C.Noise is a major problem and has not yet been recognized as such.D.Noise is a major problem about which nothing can be done.4.The author condemns noiseessentially because it.A.is against the law B.can make some people irritable C.isa nuisance D.in a ganger to people's health 5.The author would probably considerresearch about the effects noise has on people to be.A.unimportant B.impossible.C.a waste of money D.essentialACCDD 5 Is language,like food,like food,a basic human need without which achild at a critical period of life can be starved and damaged?Judging from the drasticexperiment of Frederick I in the thirteenth century,it may be hoping to discover whatlanguage a child would speak if he heard no mother tongue,he told the nurses to keepsilent.All the infants died before the first year.But clearly there was more thanlack of language here.What was missing was good mothering.Without good mothering,in the first year of life especially,the capacity to survive is seriously affected.Today no such severe lack exists as that ordered by Frederick.Nevertheless,somechildren are still backward in speaking.Most often the reason for this is that themother is insensitive to the signals of the infant,whose brain is programmed to learnlanguage rapidly.If these sensitive periods are neglected,the ideal time for acquiringskills passes and they might never be learned so easily again.A bird learns to singand to fly rapidly at right time,but the process is slow and hard once the criticalstage has passed.Experts suggest that speech stages are reached in a fixed sequenceand at a constant age,but there are cases where speech has started late in a childwho eventually turns out to be of high IQ.At twelve weeks a baby smiles and makes bowellike sounds:at twelve months he can speak simple words and understand simplecommands:at eighteen months he has a vocabulary of three to fifty words.At three heknows about 1,000 words which he can put into sentences,and at four his language differsfrom that of his parents in born with the capacity to speak.What is special about man's brain,compared with that of the monkey,is the complex system which enables a childto commect the sight and feel of,say,a toy -bear with the sound pattern "toybear".And even more incredible is the young brain's ability to pick out an orderin language from the mixture of sound around him,to analyse,to combine and recombinethe parts of a language in new ways.But speech has to be induced,and this dependson interaction between the mother and the child,where the mother recognizes the signalsin the child's babbling,grasping and smiling,and responds to them.Insensitivityof the mother to these signals dulls the interaction because the child gets discouragedand sends out only the obvious signals,Sensitivity to the child's non verbal signals is essential to the growth anddevelopment of language.1.The purpose of Frederick I's experiment was.A.to provethat children are born with ability to speak B.to discover what language a child wouldspeak without hearing any human speak C.to find out what role careful nursing wouldplay in teaching a child to speak D.to prove that a child could be damaged withoutlearning a language 2.The reason that some children are backward in speaking is mostlikely that.A.they are incapable of learning language rapidly B.they are exposed