大學英語四級閱讀理解試題及答案（四）十六Treesshouldonlybeprunedwhenthereisagoodandclearreasonfordoingsoand,fortunately,thenumberofsuchreasonsissmall.Pruninginvolvesthecuttingawayofobergrownandunwantedbranches,andtheinexperiencedgardenercanbeencouragedbythethoughtthatmoredamageresultsfromdoingitunnecessarilythanfromleavingthetreetogrowinitsownway.First,pruningmaybedonetomakesurethattreeshaveadesiredshapeorsize.Theobjectmaybetogetatreeoftherightheight,andatthesametimetohelpthegrowthofsmallsidebrancheswhichwillthickenitsappearanceorgiveitaspecialshape.Secondly,pruningmaybedonetomakethetreehealthier.Youmaycutdiseaedordeadwood,orbranchesthatarerubbingagainsteachotherandthuscausewounds.Thehealthofatreemaybeencouragedbyremovingbranchesthatareblockingupthecentreandsopreventingthefreemovementofair.Oneresultofpruningisthatanopenwoundisleftonthetreeandthisprovidesaneasyentryfordisease,butitisawoundthatwillheal.Oftenthereisaracebetweenthehealingandthedeseaseastowhetherthetreewillliveordie,sothatthereisaperiodwhenthetreeisatrisk.Itshouldbetheaimofeverygardenertoreducewhichhasbeenprunedsmoothandclean,forhealingwillbesloweddownbyroughness.Youshouldallowthecutsurfacetodryforafewhursandthenpaintitwithoneofthesubstancesavailablefromgardenshopsproducedespeciallyforthispurpose.Pruningisusuallywithoutinterferencefromtheleavesandalsoitisveryunlikelythatthecutsyumakewillbleed.Ifthisdoeshappen,itis,ofcourse,impossibletopaintthemproperly.1.Pruningshouldbedoneto______.a.makethetreegrowtallerb.improvetheshapeofthetreec.getridofthesmallbranchesd.makethesmallbranchesthicker2.Treesbecomeunhealthyifthegardener______.a.allowstoomanybranchestogrowinthemiddleb.doesnotprotectthemfromwindc.forcesthemtogrowtooquicklyd.damagessomeofthesmallsidebranches3.Whyisaspecialsubstancepaintedonthetreea.Tomakeawoundsmoothb.Topreventdiseaseenteringawoundc.Tocoveraroughsurfaced.Tohelpawoundtodry4.Agoodgardenerprunesatree______.a.atintervalsthroughouttheyearb.asquicklyaspossiblec.occasionallywhennecessaryd.regulareverywinter5.Whatwastheauthor'spurposewhenwritingthispassagea.Togivepraticalinstructionforpruningatree.b.Togiveageneraldescriptionofpruningc.Toexplainhowtreesdevelopdiseasesd.Todiscussdifferentmethodsofpruning.答案：babca十七OnThursdayafternoonMrs.Carke,dressedforgoingout,tookherhandbagwithhermoneyandherkeyinit,pulledthedoorbehindhertolockitandwenttotheover60sClub.ShealwayswentthereonThursdays.Itwasaniceoutingforanoldwomanwholivedalone.Atsixo'clockshecanehome,letherselfinandatoncesmeltcigarettesmoke.CigarettesmokeinherhouseHowHowHadsomeonegotinShecheckedthebackdoorandthewindows.Allwerelockedorfastened,asusual.Therewasnosignofforcedentry.Overacupofteashewonderedwhethersomeonemighthaveakeythatfittedherfrontdoor-"amasterkey"perhaps.SoshestayedathomethefollowingThursday.Nothinghappened.WasanyonewatchinghermovementsOntheThursdayafterthatshewentoutatherusualtime,dressedasusual,butshedidn'tgototheclub.Insteadshetookashortcuthomeagain,lettingherselfinthroughhergardenandthebackdoor.Shesettleddowntowait.Itwasjustafterfouro'clockwhenthefrontdoorbellrang.Mrs.Clarkewasmakingacupofteaatthetime.Thebellrangagain,andthensheheardherletter-boxbeingpushedopen.Withthekettleofboilingwaterinherhand,shemovedquietlytowardsthefrontdoor.Alongpieceofwireappearedthroughtheletter-box,andthenahand.Thewireturnedandcaughtaroundtheknobonthedoor-lock.Mrs.Clarkeraisedthekettleandpouredthewateroverthehand.Therewasashoutoutside,andtheskinseemedtodropoffthefingerslikeaglove.Thewirefelltothefloor,thehandwaspulledback,andMrs.Clarkeheardthesoundofrunningfeet.1.Mrs.ClarkeloodedforwardtoThursdaybecause_______.a.sheworkedataclubonthedayb.shesaidvisitorsonThursdaysc.shevisitedaclubonThursdayd.aspecialvisitorcameonThursday2.Ifsomeonehadmadeaforcedentery,_______.a.Mrs.Clarkewouldhavefoundabrokendoororwindowb.heorshewasstillinthehousec.thingswouldhavebeenthownaboutd.heorshewouldhaveneededamasterkey3.OnthethirdThursdayMrs.Clarkewentout_______.a.becauseshedidn'twanttomisstheclubagainb.toseeifthethiefwashngingaboutoutsidec.totheclubbutthenchangedhermindd.inanattempttotrickthethief4.Thelockonthefrontdoorwasonewhich_______.a.neededapieceofwiretoopenitb.couldheopenedfrominsidewithoutakeyc.could'tbeopenedwithoutakeyd.usedaknobinsteadofakey5.Thewirefeeltothefloor_______.a.becauseMrs.Clarkerefusedtoopenthedoorb.whentheman'sglovedroppedoffc.becauseitwastoohottoholdd.becausethemanjustwantedtogetaway答案：cadbd十八Manypeoplebelievetheglarefromsnowcausessnowblindnenss.Yet,darkglassesornot,theyfindthemselvessufferingfromheadachesandwateringeyes,andevensnowblindness,whenexposedtoseveralhoursof"snowlight".TheUnitedStatesArmyhasnowdeterminedthatglarefromsnowdoesnotcausesnowblindnessintroopsinasnow-coveredcountry.Rather,aman'seyesfrequentlyfindnothingtofoucsoninabroadexpanseofbarrensnow-coveredterrain.Sohisgazecontinuallyshiftsandjumpsbackandforthovertheentirelandscapeinsearchoftsomethingtolookat.Findingnothing,hourafterhour,theeyesneversotpsearchingandtheeyeballsbecomesoreandtheeyemusclesache.Natureoffsetsthisirritationbyproducingmoreandfluidwhichcoverstheeyeball.Thefluidcoverstheeyeballinincreasingquantityuntilvisionblurs,thenisobsured,andtheresultistotal,eventhoughtemporary,snowblindness.ExperimentsledtheArmytoasimplemethodofovercomingthisproblem.Scoutsaheadofamainbodyoftroopsaretrainedtoshakesnowfromevergreenbushes,creatingadottedlineastheycrosscompletelysnow-coveredlandscape,Eventhescoutsthemselvesthrowlightweight,darkcoloredobjectsaheadonwhichtheytoocanfocus.Themenfollowingcanthenseesomething.Theirgazeisarrested.Theireyesfocusonabushandhavingfoundsomethingtosee,stopscouringthesnow-blanketedlanscape.Byfocusingtheirattentionononeobjectatatime,themencancrossthesnowwithoutbecominghopelesslysnowblindorlost.Inthiswaytheproblemofcrossingasolidwhiteterrainisovercome.1.Topreventheadaches,wateringeyesandblindnesscausedbytheglarefromsnow,darkglassesare_____.a.indispensibleb.usefulc.ineffectived.available2.Whentheeyesaresoretearsareproducedto________.a.clearthevisionb.remedysnowblindnessc.easetheirritationd.loosenthemuscles3.Snowblindnessmaybeavoidedby_______.vidingtheeyeswithsomethingtofoucsond.coveringtheeyeballswithfluid4.Thescoutsshakesnowfromevergreenbushesinorderto_______.a.bivethemenbehindsomethingtoseeb.beautifythelandscapec.warmthemselvesinthecoldd.preventthemenbehindfromlosingtheirway5.Asuitabletitleforthispassagewouldbe_______.a.snowblindnessandhowtoovercomeitb.natrue'scureforsnowblindnessc.soldiersinthesnowd.snowvision答案：CCCAA十九Waterproblemsinthefuturewillbecomenoreintenseandmorecomplex.Ourincreasingpopulationwilltremendouslyincreaseurbanwastes,primarilysewage.Ontheotherhand,increasingdemandsforwaterwilldeceasesubstantialytheamountofwateravailablefordilutingwastes.Rapidlyexpandingindustrieswhichinvolvemoreandmorecomplexchemicalprocesseswillproducelargevolumesofliquidwastes,andmanyofthesewillcontainchemicalswhicharenoxious.Tofeedourrapidlyexpandingpopulation,agriculturewillhavetobeintensified.Thiswillinvolveever-increasingquantitiesofagriculturalchemicals,Fromthis,itisapparentthatdrasticstepsmustbetakenimmediatelytodevelopcorrectivemeasuresforthepollutionproblem.Therearetwowaysbywhichthispollutionproblemcanbedwindled.Thefirstrelatestothetreatmentofwastestodecreasetheirpollutionhazard.Thisinvolvestheprocessingofsolidwastes"priorto"disposalandthetreatmentofliquidwastes,orefflunets,topermitthereuseofthewaterorminimizepollutionuponfinaldisposal.Asecondapproachistodevelopaneconomicuseforallorapartofthewastes.Farmmanureisspreadinfieldsasanutrientororganicsupplement.Effluentsfromsewagedisposalplantsareusedinsomeareasbothforirrigationandforthenutrientscontained.Efflunetsfromotherprocessingplantsmayalsobeusedasasupplementalsourceofwater.Manyindustries,suchasmeatandpoultryprocessingplants,arecurrentlyconvertingformerwasteproductsintomarketablebyproducts.Otherindustriesarepotentialeonomicusesforwasteproducts.1.Thepurposeofthispassageis______.a.toalertthereadertothedwindlingwatersupplyb.toexplainindustrialusesofwaterc.toacquaintthereaderwithwaterpollutionproblemsd.todemostratevariousmeasurestosolvethepollutionproblem2.WhichofthefollowingpointsisNOTINCLUDEDinthepassagea.Industrialdevelopmentincudesthesimplificationofcomplexchemicalprocesses.b.Dilutingwastesneedscertainamountofwaterc.Demandsforwaterwillgoupalongwiththeexpandingpopulationd.Intensivecultivationoflandrequiresmoreandmorechemicals3.Thereadercanconcluedthat________.a.countriesoftheworldwillworktogetheronpolutionproblemsb.byproductsfromwastesleadtoamoreprosperousmarketplacec.scienceismakinggreatprogressonincreasingwatersuppliesd.someindustriesarenow,akingeconomicuseofwastes4.Theauthorgivessubstancetothepassagethroughtheuseof_______.erviewswithauthoritiesinthefieldofwatercontrolsb.opinionsandpersonalobservationsc.definitionswhichclarifyimportanttermsd.strongargumentsandpersuasions5.Thewords"priorto"(para.2)probablymean______.a.afterb.duringc.befored.beyond答案:cadbc二十Oneofthequalitiesthatmostpeopleadmireinothersisthewillingnesstoadmitone'smistakes.Itisextremelyhardsometimestosayasimplethinglike"Iwaswrongaboutthat,"anditisevenhardertosay,"Iwaswrong,andyouwererightaboutthat."Ihadanexperiencerecentlywithsomeoneadmittingtomethathehadmadeamistakefifteenyearsago.HetoldmehehadbeenthemanagerofacertaingrocerystoreintheneighbourhoodwhereIgrewup,andheaskedmeifIrememberedtheeggcartons.ThenherelatedanincidentandIbegantoremembervaguelytheincidenthewasdescribing.Iwasabouteightyearsoldatthetime,andIhadgomeintothestorewithmaymothertodotheweeklygroceryshopping.Onthatparticularday,Imusthavefoundmywaytothedairyfooddepartmentwheretheincidenttoodplace.Theremusthavebeenaspecialsaleoneggsthatdaybecausetherewasanimpressivedisplayofeggsindozenandhalf-dozencartons.Thecartonswerestackedthreeorfourfeethigh.Imusthavestoppedinfrontofadisplaytoadmirethestacks.Justthenawomancamebypushinghergrocerycartandknockedoffthestacksofcartons.Forsomereason,Idecideditwasuptometoputthedisplaybacktogether,soIwanttowork.Themanagerheardthemoiseandcamerushingovertoseewhathadhappened.Whenheappeared,Iwasonmykne