大学英语四级阅读理解试题含答案(四)

《大学英语四级阅读理解试题含答案(四)》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、资料大学英语四级阅读理解试题及答案（四）十六　　Treesshouldonlybeprunedwhenthereisagoodandclearreasonfordoingsoand,fortunately,thenumberofsuchreasonsissmall.Pruninginvolvesthecuttingawayofobergrownandunwantedbranches,andtheinexperiencedgardenercanbeencouragedbythethoughtthatmoredamageresults

2、fromdoingitunnecessarilythanfromleavingthetreetogrowinitsownway.　　First,pruningmaybedonetomakesurethattreeshaveadesiredshapeorsize.Theobjectmaybetogetatreeoftherightheight,andatthesametimetohelpthegrowthofsmallsidebrancheswhichwillthickenitsappearanceorgiveitaspecials

3、hape.Secondly,pruningmaybedonetomakethetreehealthier.Youmaycutdiseaedordeadwood,orbranchesthatarerubbingagainsteachotherandthuscausewounds.Thehealthofatreemaybeencouragedbyremovingbranchesthatareblockingupthecentreandsopreventingthefreemovementofair..资料　　Oneresultofpr

4、uningisthatanopenwoundisleftonthetreeandthisprovidesaneasyentryfordisease,butitisawoundthatwillheal.Oftenthereisaracebetweenthehealingandthedeseaseastowhetherthetreewillliveordie,sothatthereisaperiodwhenthetreeisatrisk.Itshouldbetheaimofeverygardenertoreducewhichhasbe

5、enprunedsmoothandclean,forhealingwillbesloweddownbyroughness.Youshouldallowthecutsurfacetodryforafewhursandthenpaintitwithoneofthesubstancesavailablefromgardenshopsproducedespeciallyforthispurpose.Pruningisusuallywithoutinterferencefromtheleavesandalsoitisveryunlikely

6、thatthecutsyumakewillbleed.Ifthisdoeshappen,itis,ofcourse,impossibletopaintthemproperly.　　1.Pruningshouldbedoneto______.　　a.makethetreegrowtaller　　b.improvetheshapeofthetree　　c.getridofthesmallbranches　　d.makethesmallbranchesthicker　　2.Treesbecomeunhealthyifthegardene

7、r______..资料　　a.allowstoomanybranchestogrowinthemiddle　　b.doesnotprotectthemfromwind　　c.forcesthemtogrowtooquickly　　d.damagessomeofthesmallsidebranches　　3.Whyisaspecialsubstancepaintedonthetree?　　a.Tomakeawoundsmooth　　b.Topreventdiseaseenteringawound　　c.Tocoveraroughsu

8、rface　　d.Tohelpawoundtodry　　4.Agoodgardenerprunesatree______.　　a.atintervalsthroughouttheyear　　b.asquicklyaspossible　　c.occa