资源描述:
《中国名校英语四级试卷5份》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、中国名校英语四级密卷(1)北京大学外语学院PartⅡReadingComprehension(35minutes)Directions:Thereare4passagesinthispart.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).Youshoulddecideonthebestchoiceandmarkthecorrespondingletteronth
2、eAnswerSheetwithasinglelinethroughthecenter.PassageOneQuestions21to25arebasedonthefollowingpassage.Antarcticahasactuallybecomeakindofspacestation—auniqueobservationpostfordetectingimportantchangesintheworld’senvironment.S1Remotefrommajorsourcesofpollutionandthecomple
3、xgeologicalandecologicalsystemsthatprevailelsewhere,Antarcticamakespossiblescientificmeasurementsthatareoftensharperandeasiertointerpretthanthosemadeinotherpartsoftheworld.GrowingnumbersofscientiststhereforeseeAntarcticaasadistantearlywarningsensor,wherepotentiallydan
4、gerousglobaltrendsmaybespottedbeforetheyshowuptothenorth.Onepromisingfieldofinvestigationisglaciology.ScholarsfromtheUnitedStates,Switzerland,andFrancearepursuingsevenseparatebutrelatedprojectsthatreflecttheirconcernforthehealthoftheWestAntarcticIceSheet—aconcerntheybel
5、ievetheworldatlargeshouldshare.TheTransantarcticMountain,someofthemmorethan14,000feethigh,dividethecontinentintotwoverydifferentregions.Thepartofthecontinenttothe“east”ofthemountainsisahighplateaucoveredbyanicesheetnearlytwomilesthick.“West”ofthemountain,thehalfoftheco
6、ntinentsouthoftheAmericasisalsocoveredbyanicesheet,buttheretheicerestsonrockthatismostlywellbelowsealevel.IftheWestAntarcticIceSheetdisappeared,thewesternpartofthecontinentwouldbereducedtoasparseclusterofisland.Whileiceandsnowareobviouslycentraltomanyenvironmentalexper
7、iments,othersfocusonthemysterious“dryvalley”ofAntarctica,valleysthatcontainlittleiceorsnoweveninthedepthsofwinter.SlashedthroughthemountainsofsouthernVictorialand,thesevalleysonceheldenormousglaciersthatdescend9,000feetfromthepolarplateautotheRossSea.Nowtheglaciersarego
8、ne,perhapsacasualtyoftheglobalwarmingtrendduringthe10,000yearssincetheiceage.Eventhesnowthatfallsinthedryvalle