月份英语四级标准模拟试题及答案详解.doc

《月份英语四级标准模拟试题及答案详解.doc》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、2012年6月份英语四级规范模拟试卷及答案详解PartIWriting(30minutes)Directions:Forthispart,youareallowed30minutestowriteacompositiononthetopicToBeCivilizedTourists.Youshouldwriteatleast120wordsfollowingtheoutlinegivenbelowinChinese:1.随着旅游人数增多，游客不文明现象突增2.分析此现象造成的不良影响3.提倡大家做文明游客ToBeCivilizedTou

2、rists______________________________________________________________________________________________________________________________________________________________PartIIReadingComprehension(SkimmingandScanning)(15minutes)Directions:Inthispart,youwillhave15minutestogoover

3、thepassagequicklyandanswerthequestionsonAnswerSheet1.Forquestions1-7,choosethebestanswerfromthefourchoicesmarked[A],[B],[C]and[D].Forquestions8-10,completethesentenceswiththeinformationgiveninthepassage.BiodiversityGenerallyspeaking,thegreatestdegreeofspeciesdiversityisf

4、oundinthewarmtropicalhabitats(thenaturalhomesofplantsoranimals)nearesttheequator.DiversityislowerintheEarth'stemperatezones,andlowestinthepolarregions,aphenomenonknownasthelatitudinalgradient(纬度倾斜度)ofbiodiversity.Andthespeciesrichnessoflandecosystems(生态系统)alsodecreasesat

5、higherelevations.Highamountsofannualrainfallalsocorrelatetoricherdiversityinlandhabitats,withthehighestconcentrationofdifferentspeciesfoundinthetropicalrainforests.Themostdiversemarineecosystemsarelocatedontheocean'scontinentalshelves,althoughdeep-seahabitatsalsodemonstr

6、atesignificantspeciesrichness.RainforestsAndCoralReefsSciencehasyettoexplaintheremarkabledegreeofspeciesdiversityfoundintropicalrainforestsandcoralreefs.Theanswerstothisecologicalmysteryinvolveboththeoriginsofdiversitythroughevolutionandthemaintenanceofspeciesdiversity.T

7、ropicalrainforestscoverapproximately9millionsquarekilometers—adecreaseofabout45%sinceman'sarrival.Althoughtheyaccountforonlyabout6%oftheworld'slandsurface,thesehighlydiverseecosystemscontainoverhalfofalllivingspecies.Someresearchersplacethatfigureashighas90%,basedonestim

8、atesofthenumberofmicroorganismsandinsectsbelievedtopopulatetherainforests.Likewise,approximatelyonequar