大学英语六级改革适用（阅读）模拟试卷12（共195题）

大学英语六级改革适用（阅读）模拟试卷12（共9套）（共195题）大学英语六级改革适用（阅读）模拟试卷第1套一、仔细阅读(本题共20题，每题1.0分，共20分。)GeneticEngineeringisaradicalandrapidlydevelopingtechnologythattouchesourlivesthroughitsapplicationinmedicine,forensics,industryandagriculture.ThroughthissciencehumansarefastinbecomingthearchitectsoflifebuttherearethosewhowarnagainsttheunknowndangersofplayingGodwhileothersseeitsbenefitsinourfightagainstdiseaseandtheproductionofabundantfoodsupplies.Inthepast50years,plantandanimalproductionhasincreaseddramatically.Today,thehumanpopulationisthelargestithaseverbeenandfortunatelyweproducemorefoodpercapitathaneverbefore.Despitethefactthatwehaveenoughfoodforeverysinglehumanbeingtohaveanadequatediet,about1billionpeoplestillsufferfrommalnutritionandhunger.Alotoftheincreaseinfoodproductionisattributedtoefficientfarmingmethodsandenvironmentalfactorssuchasirrigation,pestandweedcontrolbutthelargestcontributingfactorismodernplantandanimalbreeding.SowhatareGMfoodsandwhataretheconcernsfortheconsumer?ThemaindifferencebetweenGMfoodsandtraditionalbreedingmethodsisthedirectmodificationormanipulationofcertaingenes.Traditionalmethodsinvolvemixingthousandsofgeneswhereasgeneticmodificationallowsjustoneindividualgene,orasmallnumberofgenes,tobeinsertedintoaplant,oranimal.ThebenefitsofGMfoodsareenormous.Geneticmodificationcanbeusedtogivecropsimmunitytoplantvirusesortoimprovethenutritionalvalueofaplant.Inanimalsintendedforfood,geneticmodificationcouldpotentiallyincreasehowfastandhowbigtheygrow.Starvationonanypartoftheplanetcouldbeathingofthepastaswecouldcontroltheyield,varietiesandsizeoffoodsandproducestrainsthatareresistanttopests,areextremeintemperatureandaretoleranttoherbicides.OpponentsofGMfoodshoweverconsidertheirproductiontobetheworld'sbiggestuncontrolledbiologicalexperiment,adisasterwaitingtohappen.Thebiggestconcernsaretheeffectsthatanuncontrolledgeneticallymodifiedspeciescouldpotentiallyhaveonhumanandanimalhealth,agriculture,andontheenvironmentasawhole.Geneticallymodifiedspecieshavethepotentialtobecomebiologicalpollutantsthatarefarworsethanchemicalpollutantsastheywouldbevirtuallyimpossibletocontrolsincetheyarealive,migrateandcouldmutateproducingevenmoredangerousoffspring.Thiscouldleadtoirreversibledamagetotheecologyoftheplanet.1、Theauthordefinesgeneticengineeringas______.A、abrandnewtechnologythatwillshapeourplanetB、anupdatedtechnologythatmerelybenefithumanbeingsC、adangeroustechnologythatshouldbefunctionedinthelaboratoryD、anewandemergingtechnologythathashadaneffectonmanyaspectsofourlives标准答案：D知识点解析：细节题。原文第一段第一句话明确表明，“GeneticEngineeringisaradicalandrapidlydevelopingtechnologythattouchesourlivesthroughitsapplicationinmedicine，forensics，industryandagriculture．”即对应选项D，基因工程是一项新出现的技术．它对我们生活的方方面面产生影响。2、Whatisthemostsignificantelementfortheincreaseinfoodproduction?A、Modernplantandanimalbreeding.B、Efficientfarmingmethods.C、Environmentalfactors.D、Newirrigationsystem.标准答案：A知识点解析：细节题。根据关键词“increaseinfoodproduction”定位于第二段最后一句，“Alotoftheincreaseinfoodproductionisattributedto…butthelargestcontributingfactorismodernplantandanimalbreeding．”粮食增产归功于高效的耕作方式和一些环境因素，但最重要的是现代动植物品种的繁殖，所以，正确答案是A。选项B、C为干扰项，都是原因，但不是主要的因素。3、WhatisthemaindifferencebetweenGeneticEngineeringandtraditionallybredfoods?A、Thedifferenceliesinthemethodsandthenumberofgenes.B、Theyhavedifferentsizeandcolor.C、Traditionalmethodsarenotattractedbyconsumers.D、GeneticEngineeringismoreefficient.标准答案：A知识点解析：细节题。原文第四段第二句与第三句，明确指出传统繁殖和转基因食品的差异在于对特定遗传因子的直接改良或操作。传统的方法将数千种遗传因子混在一起．而遗传改良则把一个或少量的遗传因子注入体内。可知应选A，在方法和基因的数量上有差别。4、Whydoestheauthorclaimthatstarvationcouldbeathingofthepastinparagraph4?A、BecauseGMisimmunetoplantviruses.B、Thetemperaturecanbemodifiedbyscientists.C、Scientistswillbeabletocontrolthesize,varietyandimmunityofcropsandanimals.D、Peopleareeasilyaccessibletofoodnowadays.标准答案：C知识点解析：细节题。原文第四段最后一句，明确指出“Starvationonanypartoftheplanet…andaretoleranttoherbicides．”由于可以控制食品的生产量、变种、规格等，生产出抗虫性强，耐温性强、耐除草剂的物种，饥饿便不复存在了。选项C与原文大意相符。5、WhatisthemainoppositiontotheproductionofGMfoods?A、Chemicalpollutantsaremoredangerous.B、Thepotentialofproducingharmfuloffspringcouldnotbecontrolled.C、GMfoodsarenotproperlytested.D、Thereleaseoflargerspeciesintotheenvironment.标准答案：B知识点解析：细节题。题干问，反对转基因食品的主要理由是?文章第五段，“theywouldbevirtuallyimpossibletocontrol…”，很难去控制转基因中的有害物质，所以，正确答案是B。Therecent,apparentlysuccessfulpredictionbymathematicalmodelsofanappearanceofEINino—thewarmoceancurrentthatperiodicallydevelopsalongthePacificcoastofSouthAmerica—hasexcitedresearchers.JacobBjerknespointedoutover20yearsagohowwindsmightcreateeitherabnormallywarmorabnormallycoldwaterintheeasternequatorialPacific.Nonetheless,untilthedevelopmentofthemodelsnoonecouldexplainwhyconditionsshouldregularlyshiftfromonetotheother,ashappensintheperiodicoscillationsbetweenappearancesofthewarmEINinoandthecoldso-calledanti-ElNino.Theanswer,atleastifthecurrentmodelthatlinksthebehavioroftheoceantothatoftheatmosphereiscorrect,istobefoundintheocean.IthaslongbeenknownthatduringanElNino,twoconditionsexist:unusuallywarmwaterextendsalongtheeasternPacific,principallyalongthecoastsofEcuadorandPeru,andwindsblowfromthewestintothewarmerairrisingoverthewarmwaterintheeast.Thesewindstendtocreateafeedbackmechanismbydrivingthewarmersurfacewaterintoa"pile"thatblocksthenormalupwellingofdeeper,coldwaterintheeastandfurtherwarmstheeasternwater,thusstrengtheningthewindstillmore.ThecontributionofthemodelistoshowthatthewindsofanElNino,whichraisesealevelinthecast,simultaneouslysendasignaltothewestloweringsealevel.Accordingtothemodel,thatsignalisgeneratedasanegativeRossbywave,awaveofdepressed,ornegative,sealevel,matmoveswestwardparalleltotheequatorat25to85kilometersperday.TakingmonthstotraversethePacific,RossbywavesmarchtothewesternboundaryofthePacificbasin,whichismodeledasasmoothwallbutinrealityconsistsofquiteirregularislandchains,suchas,thePhilippinesandIndonesia.Whenthewavesmeetthewesternboundary,theyarereflected,andthemodelpredictsthatRossbywaveswillbebrokenintonumerouscoastalKelvinwavescarryingthesamenegativesea-levelsignal.Theseeventuallyshoottowardtheequator,andthenheadeastwardalongtheequatorpropelledbytherotationoftheEarthataspeedofabout250kilometersperday.WhenenoughKelvinwavesofsufficientamplitudearrivefromthewesternPacific,theirnegativesea-levelsignalovercomesthefeedbackmechanismtendingtoraisethesealevel,andtheybegintodrivethesystemintotheoppositecoldmode.Thisproducesagradualshiftinwinds,onethatwilleventuallysendpositivesea-levelRossbywaveswestward,wavesthatwilleventuallyreturnascoldcycle-endingpositiveKelvinwaves,beginninganotherwarmingcycle.6、Whichofthefollowingbestdescribestheorganizationofthefirstparagraph?A、Amodelisdescribedanditsvalueassessed.B、Aresultisreportedanditsimportanceexplained.C、Aphenomenonisnotedanditssignificancedebated.D、Ahypothesisisintroducedandcontraryevidencepresented.标准答案：B知识点解析：推断题。根据第一段的整体结构Therecent，apparentlySuccessfulprediction．．．hasexcitedresearchers．．．Nonetheless．untilthedevelopmentofthemodelsnoonecouldexplainwhy…分析．该段首先介绍了数学模式对厄尔尼诺现象的发生进行了成功的预测，这次预测鼓舞了研究人员。而这些数学模式发展出来之前．没有人能够解释为什么这些状况发生期间出现周期性的变化。由这些分析可推知该段的逻辑顺序是先报道了一个结果，然后解释了它的重要性，和B选项表达一致。7、Accordingtothepassage,whichofthefollowingfeaturesischaracteristicofanElNino?A、ColdcoastalwaternearPeru.B、Windblowingfromthewest.C、Randomoccurrence.D、Worldwideeffects.标准答案：B知识点解析：细节题。联系第二段段首对厄尔尼诺现象的解释IthaslongbeenknownthatduringanElNino，twoconditionsexist：unusuallywarmwaterextendsalongtheeasternPacific，principallyalongthecoastsofEcuadorandPeru，andwindsblowfromthewestintothewarmerairrisingoverthewarmwaterintheeast．“人们早就知道，在厄尔尼诺现象发生期间，存在两种现象——一是异常的暖流沿着太平洋东海岸延伸。尤其是沿着厄瓜多尔和秘鲁的海岸延伸．二是从西方来的季风吹进在东方暖流中产生的更暖的空气中。”可知选项B中windsblowingfromthewest“从西方来的季风”是厄尔尼诺现象的一种特征，所以答案选B。8、Whichofthefollowing,iftrue,wouldmostseriouslyunderminethevalidityofthemodelElNinothatispresentedinthepassage?A、ElNinoextendsmuchfartheralongthecoastsofEcuadorandPeruduringsomeyears.B、TherisingofcoldwaterintheeasternPacificdependsonthelocalcharacters.C、ThevariationsinthetimeforRossbywavestocrossthePacificrelyonthewindpower.D、ThePacificirregularwesterncoasthindersmostKelvinwavesfromheadingeastward.标准答案：D知识点解析：细节题。根据第二段最后一句即花费数月时间穿越太平洋后，“罗斯比波波浪”来到太平洋盆地的西部边缘——该盆地被模拟成平坦的屏障，但实际上包含很不规则的岛屿群。可知，该模式依据的是太平洋盆地的西部边缘是平坦的。而如果不是这样，则该模式就不正确。通读答案，D选项内容太平洋不规律规则的西部海岸阻碍了大多数开氏波浪流向东部和原文表述一致，所以答案选D。9、Accordingtothemodelpresentedinthepassage,whichofthefollowingnormallysignalsthedisappearanceofanElNino?A、ThearrivalintheeasternPacificofnegativesea-levelKelvinwaves.B、Ashiftinthedirectionofthewindsproducedbyananti-ElNino.C、ThereflectionofKelvinwavesreachingtheeasternborderofthePacific.D、AnincreaseinthespeedatwhichnegativeRossbywavescrossthePacific.标准答案：A知识点解析：推断题。联系原文第二、三段内容，第二段介绍了厄尔尼诺现象存在的两种现象——异常的暖流沿着太平洋东海岸延伸和从西方来的季风吹进在东方暖流中产生的更暖的空气中。第三段指出．如果从西部来的“开氏波浪”达到足够的量．它们就会克服提升海平面的反馈机制，促使该机制变成相反的寒冷模式，进而导致季风的逐渐转变。最终促使“罗斯比波浪”向西流动．寒冷的“开氏波浪”结束循环返回。开始另一个暖流循环。这说明，“开氏波浪”的返回就预示着厄尔尼诺现象的结束。和选项A的表述一致。10、Theprimarypurposeofthetextasawholeisto______.A、introduceanewexplanationofphysicalphenomenonB、explainthedifferencebetweentwonaturalphenomenaC、illustratethelimitsofapplyingmathematicstocomplexproblemsD、clarifythedistinctionbetweenanoldexplanationandanewmodel标准答案：A知识点解析：主旨题。回顾全文。第一段提到了利用数学模式对厄尔尼诺现象的发生进行的预测，接着介绍了该模式的重要性，第二、三段具体介绍了该模式的观点。这说明，本文主要是在介绍对厄尔尼诺现象的一种新解释。所以答案选A。Aidedbytherecentabilitytoanalyzesamplesofairtrappedinglaciers,scientistsnowhaveaclearerideaoftherelationshipbetweenatmosphericcompositionandglobaltemperaturechangingoverthepast160,000years.Inparticular,determinationofatmosphericcompositionduringperiodsofglacialexpansionandretreat(coolingandwarming)ispossibleusingdatafromthe2,000meterVostokicecoredrilledinAntarctica.Thetechniqueinvolvedissimilartothatusedinanalyzingcoresofmarinesediments,wheretheratioofthetwocommonisotopesofoxygen,180and160,accuratelyreflectspasttemperaturechanges.IsotopicanalysisofoxygenintheVostokcoresuggestsmeanglobaltemperaturefluctuationsofupto10degreescentigradeoverthepast160,000years.DatafromtheVostokcorealsoindicatethattheamountofcarbondioxidehasfluctuatedwithtemperatureoverthesameperiod:thehigherthetemperature,thehighertheconcentrationofcarbondioxideandthelowerthetemperature,thelowertheconcentration.Althoughchangeincarbondioxidecontentcloselyfollowschangeintemperatureduringperiodsofdeglaciation,itapparentlylagsbehindtemperatureduringperiodsofcooling.Thecorrelationofcarbondioxidewithtemperature,ofcourse,doesnotestablishwhetherchangesinatmosphericcompositioncausingthewarmingandcoolingtrendsorwerecausedbythem.ThecorrelationbetweencarbondioxideandtemperaturethroughouttheVostokrecordisconsistentandpredictable.Theabsolutetemperaturechanges,however,arefrom5to14timesgreaterthanwouldbeexpectedonthebasisofcarbondioxide'sownabilitytoabsorbinfraredradiation,orradiantheat.Thisreactionsuggeststhat,quiteasidefromchangesinheat-trappinggases,commonlyknownasgreenhousegases,certainpositivefeedbacksarealsoamplifyingthetemperaturechange.Suchfeedbacksmightinvolveiceonlandandsea,clouds,orwatervapor,whichalsoabsorbradiantheat.OtherdatafromtheVostokcoreshowthatmethanegasalsocorrelatescloselywithtemperatureandcarbondioxide.Themethaneconcentrationnearlydoubled,forexample,betweenthepeakofthepenultimateglacialperiodandthefollowinginterglacialperiod.Withinthepresentinterglacialperiodithasmorethandoubledinjustthepast300yearsandisrisingrapidly.Althoughtheconcentrationofatmosphericmethaneismorethantwoordersofmagnitudelowerthanthatofcarbondioxide,itcannotbeignored:theradiativepropertiesofmethanemakeit20timesmoreeffective,moleculeformolecule,thancarbondioxideinabsorbingradiantheat.Onthebasisofasimulationmodelthatclimatologicalresearchershavedeveloped,methaneappearstohavebeenabout25percentasimportantascarbondioxideinthewarmingthattookplaceduringthemostrecentglacialretreat8,000to10,000yearsago.11、Theprimarypurposeofthepassageisto______.A、interpretdataB、explainresearchmethodologyC、evaluateaconclusionD、suggestanewtechnique标准答案：A知识点解析：主旨题。根据文章第一、二、四段的首句Aidedbytherecentabilitytoanalyzesamplesofairtrappedinglaciers，scientistsnowhaveacleareridea…，DatafromtheVostolkcorealsoindicatethat…．OtherdatafromtheVostokcoreshowthat…可以把握文章的主要目的是科学家通过对困在冰川中的空气样品进行分析．对大气构成与全球气温变化之间的关系进行解释说明。简而言之，就是“解释数据”，和A选项表达一致。12、Accordingtothepassage,whichofthefollowingstatementsbestdescribestherelationshipbetweencarbondioxideandglobaltemperature?A、Carbondioxidelevelschangeimmediatelyinresponsetochangesintemperature.B、Carbondioxidelevelscorrelatewithglobaltemperatureduringcoolingperiodsonly.C、Duringcoolingperiods,carbondioxidelevelsinitiallyremainhighandthendecline.D、Carbondioxidelevelsincreasemorequicklythanglobaltemperaturedoes.标准答案：C知识点解析：细节题。根据“therelationshipbetweencarbondioxideandglobaltemperature”定位到文章第二段。Althoughchangeincarbondioxidecontentcloselyfollowschangeintemperatureduringperiodsofdeglaciation，itapparentlylagsbehindtemperatureduringperiodsofcooling．“尽管在冰川消退期，二氧化碳含量的变化紧随着气温的变化，但在降温期，二氧化碳含量的变化显然滞后于气温。”说明降温期二氧化碳含量先升后降，比气温下降慢一步，和选项C表述一致，所以C为正确答案。同时也排除了A“二氧化碳对气温变化做出的反应是迅速的”和B“二氧化碳含量仅在降温期和气温有关”。D“二氧化碳比气温升得更快”属于无中生有。所以答案选C。13、Theauthormentions"certainpositivefeedbacks"(Line6,Para.3)inordertoindicatethat______.A、increasedconcentrationofcarbondioxideintheEarth’satmosphereisresponsibleforglobaltemperatureincreaseB、someclimatesimulationmodelshaveproducedusefulinformationC、greenhousegasesalonedonotaccountforglobaltemperatureincreaseD、variablesthatbenefitlifearecausingglobaltemperaturetoincrease标准答案：C知识点解析：细节题。根据第三段Thisreactionsuggeststhat，quiteasidefromchangesinheat—trappinggases，commonlyknownasgreenhousegases，certainpositivefeedbacksarealsoamplifyingthetemperaturechange．Suchfeedbacksmightinvolveiceonlandandsea，clouds，orwatervapor，whichalsoabsorbradiantheat．“这种关系表明，除了捕热气体(即通常所称为的温室气体)以外，某些正反馈也会扩大温度变化。此类反馈可能涉及陆地上和海洋中的冰、云或水蒸气，它们也都会吸收辐射热。”可知不仅仅是温室气体导致了温度升高．某些正反馈也是原因之一。C选项和原文表述一致。所以答案选C。14、Accordingtothepassage,whichofthefollowingstatementsaboutmethaneistrue?A、Methaneisfoundinmarinesediments.B、Methaneismoreeffectivethancarbondioxideinabsorbingradiantheat.C、TheEarth’satmospherenowcontainsmorethantwiceasmuchmethaneasitdoescarbondioxide.D、ThehighertheconcentrationofcarbondioxideintheEarth’satmosphere,thelowertheconcentrationofmethane.标准答案：B知识点解析：细节题。根据“methane”定位到第四段。根据Althoughtheconcentrationofatmosphericmethaneismorethantwoordersofmagnitudelowerthanthatofcarbondioxide，itcannotbeignored：theradiativepropertiesofmethanemakeit20timesmoreeffective，moleculeformolecule，thancarbondioxideinabsorbingradiantheat．“尽管大气甲烷的含量要比二氧化碳的含量低两个多数量级，但它仍不能被忽视：就分子与分子相对比，甲烷的辐射特性使其在吸收辐射热这方面，要比二氧化碳强出20倍。”说明甲烷在吸收辐射热这方面比二氧化碳有效。和选项B的表述一致，所以答案是B。A“甲烷是在海洋沉积物中发现的”原文没有提及．C是对原文“甲烷的含量几乎翻了一倍。在目前的间冰期范围内，它在过去短短的300年就已经增加了两倍多，并正在迅速增长”的误解，D“二氧化碳含量越高，甲烷含量越低”也没有提及。15、ThepassagesuggeststhatwhenthemethaneconcentrationintheEarth’satmospheredecreases,whichofthefollowingalsohappens?A、Glaciersmeltfaster.B、Theconcentrationofcarbondioxideincreases.C、Carbondioxideabsorbsmoreradiantbeat.D、Theglobaltemperaturedecreases.标准答案：D知识点解析：推断题。根据文章最后一段的最后一个例子“从气候学研究者所建立的某个模拟模型来看，在8000至10000年之前的最近一次冰川稍退期间发生的升温过程中，甲烷似乎发挥了相等于二氧化碳25％的重要作用。”可知温度升高，甲烷含量升高，二者关系是正相关。那么如果甲烷含量下降，温度应该会降低．所以答案选D。Oneofthesimplestandbestknownkindsofcrystalistheionicsalt,ofwhichatypicalexampleissodiumchloride,orordinarytablesalt.Thefundamentalcomponentsofanionicsaltareions:atomsormoleculesthathavebecomeelectricallychargedbygainingorlosingonemoreelectrons.Informingsodiumchloride,forexample,sodiumatomsgiveupanelectron(therebybecomingpositivelycharged)andchlorineatomsgainanelectron(therebybecomingnegativelycharged).Theionsareattractedtooneanotherbytheiroppositecharges,andtheystacktogethercompactly,liketightlypackedspheres.Recently,scientistsatMichiganStateUniversitycreatedanewkindofcrystalcalledanelectride.Inelectrides,theanions(negativeions)arecompletelyreplacedbyelectrons,whicharetrappedinnaturallyformedcavitieswithinaframeworkofregularlystackedcations(positiveions).Electridesarethefirstexamplesofionicsaltsinwhichalltheseanionicsitesareoccupiedsolelybyelectrons.Unlikeothertypesofanions,anionicelectronsdonotbehaveasiftheyweresimplechargedspheres.Inparticular,becauseoftheirlowmassandtheirtendencytointeractwithoneanotherovergreatdistances,theycannotbe"pinneddown"toanyonelocation.Instead,theywanderclosetoandamongtheatomsliningthecavityandinteractwithelectronsinnearbycavities,perhapschangingplaceswiththem.Thepropertiesofanelectridedependlargelyonthedistancebetweenthecavitiesthatholdtrappedelectrons.Whenthetrappedelectronsarefarapart,theydonotinteractstrongly,andsobehavesomewhatlikeanarrayofisolatednegativecharges.Whentheyareclosertogether,theybegintodisplaypropertiesassociatedwithlargeensemblesofidenticalparticles.Whentheyarestillcloser,theensemblepropertiesdominateandtheelectrons"delocalize":theyarenolongertightlyboundwithinindividualcavitiesbutaremoreorlessfreetopassthroughthespaceswithintheframeworkofpositiveions.Bysynthesizingelectridesfromavarietyofmaterials,onecanvarythegeometryoftheanioniccavitiesandtheirrelationtothesurroundingcations.Theresultingpropertiesmaymakeitpossibleforelectridestobecomeabasisforeconomicallyusefulnewmaterialsanddevices.Forinstance,becausetheelectronsinsomeelectridesareveryweaklybound,thesecrystalscouldbeeffectiveasphotosensitivedetectors,inwhichanimpingingphotonliberatesanelectron,resultinginasmallelectriccurrent.Thesameweakbindingcouldalsomakeelectridesusefulinsolarenergyconvertersandascathodesinbatteries.Oneobstacleisthetendencyofelectridestodecomposethroughreactionwithairandwater.Researchersareseekingwaystoincreasetheirstability.16、Thetextisprimarilyconcernedwithdiscussing______.A、awaytoisolateelectronsB、thecharacteristicsofanewkindofcrystalC、thestructureofanionicsaltD、commercialusesforelectrides标准答案：B知识点解析：主旨题。文章第一段讲了普通的晶体，第二段是解答本题的关键，第二段中介绍了最近的科研发现——电子晶体．后文都是在介绍这种新的电子晶体的特征，和B选项表达一致。所以答案选B。17、Inthefirstparagraph,theauthorisprimarilyconcernedwith______.A、introducingavariantonthestandardatomictheoryB、describinghowchlorineatomscanbecomenegativelychargedC、providingbackgroundforthetechnicaldiscussiontofollowD、describingsomeearlyresearchatMichiganStateUniversity标准答案：C知识点解析：推断题。根据第1题的讨论结果，文章第二段开始一直关注的是新的科研发现——电子晶体，只有第一段的内容是普通的晶体，所以第一段内容是为引起下文而进行的学科普遍现象背景介绍．为后文进行铺垫。同时也和下文形成了对比。和选项C表述一致，所以C为正确答案。18、Accordingtothetext,thedefiningcharacteristicofanelectrideiswhichofthefollowing?A、Itspositiveisofparticularlylowmass.B、Itsionspossessidenticalelectricalcharges.C、Itcontainsaframeworkofregularlystackedions.D、Itsnegativeionsconsistsolelyofelectrons.标准答案：D知识点解析：细节题。根据“electride”定位到第二段Inelectrides，theanions(negativeions)arecompletelyreplacedbyelectrons，whicharetrappedinnaturallyformedcavitieswithinaframeworkofregularlystackedcations(positiveions)．Electridesarethefirstexamplesofionicsaltsinwhichalltheseanionicsitesareoccupiedsolelybyelectrons．“在电子晶体中，阴离子(即带负电荷的离子)全部被电子替代，这些电子被困在自然形成的空穴中，而空穴位于规则堆砌的阳离子(即带正电荷的离子)的框架内。电子晶体是一种阴离子空间全被电子占据的离子盐。“可知电子晶体的阴离子完全是由电子构成的，D选项和原文表述一致，所以答案选D。19、Itcanbeinferredfromthetextthatanionsbehavingas"simplechargedspheres"(Para.3)couldbeexpectedto______.A、readilyloseelectronsandbecomepositivelychargedB、movefreelyinandoutoftheircavitiesC、respondtophotonsbyliberatingelectronsD、remainfixedrelativetotheircations标准答案：D知识点解析：推断题。根据第三段内容．大意是“和其他类型的阴离子不同，作为阴离子的电子不像那些简单的带电球体。它们很特别，由于它们的质量很小而且有与远距离的离子进行相互作用的倾向。它们不会被固定在任何一个位置。相反，它们会到处游离，或者紧靠那些在空穴边上的原子，或者在这些原子之间游离，并且还和附近空中的电子发生相互作用，甚至还可能与它们交换位置。”可知那些简单的带电球体的阴离子会被固定，不会到处游离，和选项D的表述一致，所以答案是D。20、Withwhichofthefollowingstatementsregardingelectrideswouldtheauthormostlikelyagree?A、Theyhaveproventhemselvestobeofgreatcommercialvalue.B、Theirfuturecommercialvalueispromisingbutuncertain.C、Theyareinterestingbutofnopracticalvalue.D、Theyhavecommercialvaluemainlyinsolarenergyapplications.标准答案：B知识点解析：推断题。根据文章最后一段的Thesameweakbindingcouldalsomakeelectridesusefulinsolarenergyconvertersandascathodesinbatteries．Oneobstacleisthetendencyofelectridestodecomposethroughreactionwithairandwater．Researchersareseekingwaystoincreasetheirstability．“这种结合微弱的特性同样可使电子晶体对太阳能转换器和电池的阴极很有用。可电子晶体的一个缺陷在于它易于与空气和水发生反应而分解。目前，研究人员正设法寻找提高电子晶体稳定性的方法。”可知电子晶体对于太阳能转换器和电池的阴极很有用，是存在商业价值的。但是由于本身的缺陷，研究人员正在努力改进，所以它的商业前景尚不明朗。和选项B的表述一致。所以答案选B。大学英语六级改革适用（阅读）模拟试卷第2套一、仔细阅读(本题共20题，每题1.0分，共20分。)Therewasatimewhenbig-leagueuniversitypresidentsreallymattered.TheNewYorkTimescoveredtheireverymove.Presidents,therealones,soughttheircounsel.ForWoodrowWilsonandDwightEisenhower,beingheadofPrincetonandColumbia,respectively,wasastepping-stonetotheWhiteHouse.Today,though,thejobofcollegepresidentislessandlessremovedfromthatoftheAvonlady(exceptthehousecallsaremadetothedoorstepsofwealthyalums).RuthSimmons,thenewlyinstalledpresidentofBrownUniversityandthefirstAfricanAmericantoleadanIvyLeagueschool,isathrowbacktothecrusadingcampusleadersoftheold.Shedoesn'tmerelymarshalfunds;sheinveststheminthegreateducationalcausesofourday.Withthemorethan$300millionsheraisedaspresidentofSmithCollegefrom1995to2001,Simmonsestablishedanengineeringprogram(thefirstatanywomen'sschool)andaddedseminarsfocusedonpublicspeakingtopurgetheubiquitous"likes"and"urns"fromthecampusidiom.AtameetingtodiscussthefutureofSmith'smathdepartment,oneprofessortimidlyrequestedtwomorediscussionsectionsforhiscourse.Herresponse:"Dreambigger."Herowndreamwasborninasharecropper'sshackinEastTexaswheretherewasnomoneyforbooksortoys—sheandher11siblingseachgotanapple,anorangeand10nutsforChristmas.ThoughshewascalledNegroonherwalktoschool,enteringtheclassroom,shesays,"waslikewakingup."WhenSimmonswonascholarshiptoDillardUniversity,herhighschoolteacherstookupacollectionsoshe'dhaveacoat.ShewentontoHarvardtoearnaPh.D.inRomancelanguages.SimmonshasmadediversityherNo.1campuscrusade.ShenearlydoubledtheenrolmentofblackfreshmenatSmith,largelybytravellingtohighschoolsinthenation'spoorestZIPcodestorecruit.Concernedwiththelivesofminoritystudentsoncetheyarrivedatschool,shehasfoughttoeasetheracialstandoffsthatplaguesomanycampuses.AtSmithsheturneddownarequestbystudentstohaverace-specificdorms.In1993,whileviceprovostatPrinceton,shewroteanowfamousreportrecommendingthattheuniversityestablishanofficeofconflictresolutiontodefuseracialmisunderstandingsbeforetheyboiledover.HerfirsttaskatBrownwillbetohealonesuchrupturelastspringafterthestudentpaperpublishedanincendiaryadbyconservativepolemicistDavidHorowitzarguingthatblackseconomicallybenefitedfromslavery."There'snosafegroundforanybodyinracerelations,butcampuses,unlikeanyotherinstitutioninoursociety,providetheopportunitytocrossraciallines,"saysSimmons."Andevenifyou'rehurt,youcan'twalkaway.Youhavetowalkoverthatline."1、Whatdoesthe"ones"(Line2,Para.l)referto?A、CounsellorsintheWhiteHouseB、FamouspeopleinacountryC、PresidentsofuniversitiesD、Presidentsofnations标准答案：D知识点解析：语义题。定位于原文中“Presidents，therealones，soughttheircounsel．”该段第一句说一流大学的校长举足轻重。该句意思是总统甚至都向他们征求意见，所以该句的their指代大学校长，而ones指代国家总统。所以，选项D是正确答案。2、WhichoneofthefollowingisNOTTRUEonhowSimmonsspendwiththefundsshehadraised?A、Sheenlargedthenumberofthosestudentswhocanwinscholarship.B、Shepaidmoreattentiononpublicspeakingbyaddingmoreseminars.C、Anengineeringprogramwasestablishedbyher.D、Sheencouragedprofessorstopracticetheirideas.标准答案：A知识点解析：细节题。题干问，关于Simmons校长怎么利用她筹集的款项，选项中哪一项不正确?此题定位于原文第二段。选项B，对应原文“addedseminarsfocusedonpublicspeaking”；选项C，对应“Simmonsestablishedanengineeringprogram”；选项D，原文中一位教授提出他的课能否多加两次讨论环节，Simmons回答说再大胆些。可知她是鼓励教授们实践自己的想法的。选项A，她增加了获得奖学金的人数，文中并未提及。故选A。3、Whatcanweinferfrom"waslikewakingup"inparagraph3?A、Simmonsisrealistic.B、Simmonsiscreative.C、Simmonsiscoward.D、Simmonsisoptimistic.标准答案：D知识点解析：推断题。原文第三段讲述Simmons年少时的经历。原文第二句“ThoughshewascalledNegroonherwalktoschool，enteringtheclassroom，shesays，“waslikewakingup．”上学时有人叫她黑鬼。但她进教室却说：“这唤醒了我。”然后奋发努力取得奖学金并在哈佛取得博士学位。由此可看出，她非常乐观，选项D符合逻辑。选项A，现实的；选项B，创新的；选项C，胆小的，均与原文大意不相符。故选D。4、WhydidSimmonsrejecttherequesttoallowstudentswithsameracetolivetogetherinonedormitory?A、Sheintendedtoallowstudentstomakemorefriends.B、Sheexpectedstudentsfromdifferentracestoknowmoreabouteachot