大学英语四级阅读理解试题及答案.

大学英语四级阅读理解试题及答案（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.Whyisaspecialsubstancepaintedonthetree?a.Tomakeawoundsmoothb.Topreventdiseaseenteringawoundc.Tocoveraroughsurfaced.Tohelpawoundtodry4.Agoodgardenerprunesatree______.a.atintervalsthroughouttheyearb.asquicklyaspossiblec.occasionallywhennecessaryd.regulareverywinter5.Whatwastheauthor'spurposewhenwritingthispassage?a.Togivepraticalinstructionforpruningatree.b.Togiveageneraldescriptionofpruningc.Toexplainhowtreesdevelopdiseasesd.Todiscussdifferentmethodsofpruning.答案：babca十七OnThursdayafternoonMrs.Carke,dressedforgoingout,tookherhandbagwithhermoneyandherkeyinit,pulledthedoorbehindhertolockitandwenttotheover60sClub.ShealwayswentthereonThursdays.Itwasaniceoutingforanoldwomanwholivedalone.Atsixo'clockshecanehome,letherselfinandatoncesmeltcigarettesmoke.Cigarettesmokeinherhouse?How?How?Hadsomeonegotin?Shecheckedthebackdoorandthewindows.Allwerelockedorfastened,asusual.Therewasnosignofforcedentry.Overacupofteashewonderedwhethersomeonemighthaveakeythatfittedherfrontdoor-amasterkeyperhaps.SoshestayedathomethefollowingThursday.Nothinghappened.Wasanyonewatchinghermovements?OntheThursdayafterthatshewentoutatherusualtime,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,whenexposedtoseveralhoursofsnowlight.TheUnitedStatesArmyhasnowdeterminedthatglarefromsnowdoesnotcausesnowblindnessintroopsinasnow-coveredcountry.Rather,aman'seyesfrequentlyfindnothingtofoucsoninabroadexpanseofbarrensnow-coveredterrain.Sohisgazecontinuallyshiftsandjumpsbackandforthovertheentirelandscapeinsearchoftsomethingtolookat.Findingnothing,hourafterhour,theeyesneversotpsearchingandtheeyeballsbecomesoreandtheeyemusclesache.Natureoffsetsthisirritationbyproducingmoreandflu