大学英语四级阅读理解试题（卷）与答案解析(四)

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1、WORD文档可编辑大学英语四级阅读理解试题及答案（四）十六　　Treesshouldonlybeprunedwhenthereisagoodandclearreasonfordoingsoand,fortunately,thenumberofsuchreasonsissmall.Pruninginvolvesthecuttingawayofobergrownandunwantedbranches,andtheinexperiencedgardenercanbeencouragedbythethoughtthatmoredamageresultsfromdoi

2、ngitunnecessarilythanfromleavingthetreetogrowinitsownway.　　First,pruningmaybedonetomakesurethattreeshaveadesiredshapeorsize.Theobjectmaybetogetatreeoftherightheight,andatthesametimetohelpthegrowthofsmallsidebrancheswhichwillthickenitsappearanceorgiveitaspecialshape.Secondly,pruning

3、maybedonetomakethetreehealthier.Youmaycutdiseaedordeadwood,orbranchesthatarerubbingagainsteachotherandthuscausewounds.Thehealthofatreemaybeencouragedbyremovingbranchesthatareblockingupthecentreandsopreventingthefreemovementofair.技术资料专业分享WORD文档可编辑　　Oneresultofpruningisthatanopenwoun

4、disleftonthetreeandthisprovidesaneasyentryfordisease,butitisawoundthatwillheal.Oftenthereisaracebetweenthehealingandthedeseaseastowhetherthetreewillliveordie,sothatthereisaperiodwhenthetreeisatrisk.Itshouldbetheaimofeverygardenertoreducewhichhasbeenprunedsmoothandclean,forhealingwi

5、llbesloweddownbyroughness.Youshouldallowthecutsurfacetodryforafewhursandthenpaintitwithoneofthesubstancesavailablefromgardenshopsproducedespeciallyforthispurpose.Pruningisusuallywithoutinterferencefromtheleavesandalsoitisveryunlikelythatthecutsyumakewillbleed.Ifthisdoeshappen,itis,

6、ofcourse,impossibletopaintthemproperly.　　1.Pruningshouldbedoneto______.　　a.makethetreegrowtaller　　b.improvetheshapeofthetree　　c.getridofthesmallbranches　　d.makethesmallbranchesthicker　　2.Treesbecomeunhealthyifthegardener______.技术资料专业分享WORD文档可编辑　　a.allowstoomanybranchestogrowinthemi

7、ddle　　b.doesnotprotectthemfromwind　　c.forcesthemtogrowtooquickly　　d.damagessomeofthesmallsidebranches　　3.Whyisaspecialsubstancepaintedonthetree?　　a.Tomakeawoundsmooth　　b.Topreventdiseaseenteringawound　　c.Tocoveraroughsurface　　d.Tohelpawoundtodry　　4.Agoodgardenerprunesatree______.　　

8、a.atintervalsthroughoutthe