英语等级考试题一级练习附答案英语等级考试题一级精选练习附答案Idealarelikethestars---weneverreachthem,butlikemariners,wechartourcoursebythem.以下是小编为大家搜索整理的英语等级考试题一级精选练习附答案，希望对正在关注的您有所帮助!更多精彩内容请及时关注我们应届毕业生考试网!AntarcticaandEnvironmentAntarcticahasactuallybecomeakindofspacestation-auniqueobservationpostfordetectingimportantchangesintheworld‘senvironment.Remotefrommajorsourcesofpollutionandthecomplexgeologicalandecologicalsystemsthatprevailelsewhere，Antarcticamakespossiblescientificmeasurementsthatareoftensharperandeasiertointerpretthanthosemadeinotherpartsoftheworld.GrowingnumbersofscientiststhereforeseeAntarcticaasadistant-early-warningsensor，wherepotentiallydangerousglobaltrendsmaybespottedbeforetheyshowuptothenorth.Onepromisingfieldofinvestigationisglaciology.ScholarsfromtheUnitedStates，Switzerland，andFrancearepursuingsevenseparatebutrelatedprojectsthatreflecttheirconcernforthehealthoftheWestAntarcticIceSheet-aconcerntheybelievetheworldatlargeshouldshare.TheTransantarcticMountain，someofthemmorethan14，000feethigh，dividethecontinentintotwoverydifferentregions.Thepartofthecontinenttothe“east”ofthemountainsisahighplateaucoveredbyanicesheetnearlytwomilesthick.“West”ofthemountain，thehalfofthecontinentsouthoftheAmericasisalsocoveredbyanicesheet，buttheretheicerestsonrockthatismostlywellbelowsealevel.IftheWestAntarcticIceSheetdisappeared，thewesternpartofthecontinentwouldbereducedtoasparseclusterofisland.Whileiceandsnowareobviouslycentraltomanyenvironmentalexperiments，othersfocusonthemysterious“dryvalley”ofAntarctica，valleysthatcontainlittleiceorsnoweveninthedepthsofwinter.SlashedthroughthemountainsofsouthernVictoriaLand，thesevalleysonceheldenormousglaciersthatdescended9，000feetfromthepolarplateautotheRossSea.Nowtheglaciersaregone，perhapsacasualtyoftheglobalwarmingtrendduringthe10，000yearssincetheiceage.Eventhesnowthatfallsinthedryvalleysisblastedoutbyviciouswindsthatroarsdownfromthepolarplateautothesea.Leftbarearespectaculargorges，rippledfieldsofsanddunes，cl