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2015年北京师范大学考博英语真题试卷(总分68,做题时间90分钟)1.ReadingComprehensionThehumanearcontainstheorganforhearingandtheorganforbalance.Bothorgansinvolvefluid-filledchannelscontaininghaircellsthatproduceelectrochemicalimpulseswhenthehairsarestimulatedbymovingfluid.Theearcanbedividedintothreeregions:outer,middle,andinner.Theouterearcollectssoundwavesanddirectsthemtotheeardrumseparatingtheouterearfromthemiddleear.Themiddleearconductssoundvibrationsthroughthreesmallbonestotheinnerear.Theinnerearisanetworkofchannelscontainingfluidthatmovesinresponsetosoundormovement.Toperformthefunctionofhearing,theearconvertstheenergyofpressurewavesmovingthroughtheairintonerveimpulsesthatmebrainperceivesassound.Vibratingobjects,suchasthevocalcordsofaspeakingperson,createwavesinmesurroundingair.Thesewavescausetheeardrumtovibratewiththesamefrequency.Thethreebonesofthemiddleearamplifyandtransmitthevibrationstotheovalwindow,amembraneonthesurfaceofthecochlea,theorganofhearing.Vibrationsofmeovalwindowproducepressurewavesinthefluidinsidemecochlea.Haircellsinthecochleaconverttheenergyofthevibratingfluidintoimpulsesthattravelalongtheauditorynervetothebrain.Theorganforbalanceisalsolocatedintheinnerear.Sensationsrelatedtobodypositionaregeneratedmuchlikesensationsofsound.Haircellsintheinnerearrespondtochangesinheadpositionwithrespecttogravityandmovement.Gravityisalwayspullingdownonthehairs,sendingaconstantseriesofimpulsestothebrain.Whenthepositionoftheheadchanges—aswhentheheadbendsforward—theforceonthehaircellschangesitsoutputofnerveimpulses.Thebraintheninterpretsthesechangestodeterminethehead'snewposition.1.Whatcanbeinferredabouttheorgansforhearingandbalance?ABothorgansevolvedinhumansatthesametime.BBothorganssendnerveimpulsestothebrain.CBothorganscontainthesameamountoffluid.DBothorgansarelocatedinmeear'smiddleregion.2.HearinginvolvesallofthefollowingEXCEPT______.AmotionofthevocalcordssothattheyvibrateBstimulationofhaircellsinfluid-filledchannelsCamplificationofsoundvibrationsDconversionofwaveenergyintonerveimpulses3.ItcanbeinferredfromParagraphs2and3thatthecochleaisapartof______.AtheouterearBmeeardrumCthemiddleearDtheinnerear4.WhatcanbeinferredfromParagraph4aboutgravity?AGravityhasanessentialroleinthesenseofbalance.BTheearconvertsgravityintosoundwavesintheair.CGravityisaforcethatoriginatesinthehumanear.DTheorganforhearingisnotsubjecttogravity.5.Inthispassage,theauthormainlyexplains______.AtheorgansofthehumanearBthefunctionofthehearingCthethreeregionsoftheearDhowtheearorganperformsthehearingandbalanceThegeologyoftheEarth'ssurfaceisdominatedbytheparticularpropertiesofwater.PresentonEarthinsolid,liquid,andgaseousstates,waterisexceptionallyreactive.Itdissolves,transports,andprecipitatesmanychemicalcompoundsandisconstantlymodifyingthefaceoftheEarth.Evaporatedfromtheoceans,watervaporformsclouds,someofwhicharetransportedbywindoverthecontinents.Condensationfromthecloudsprovidestheessentialagentofcontinentalerosion:rain.Precipitatedontotheground,thewatertricklesdowntoformbrooks,streams,andrivers,constitutingwhatiscalledthehydrographicnetwork.Thisimmensepolarizednetworkchannelsthewatertowardasinglereceptacle:anocean.Gravitydominatesthisentirestepinthecyclebecausewatertendstominimizeitspotentialenergybyrunningfromhighaltitudestowardthereferencepointthatissealevel.Therateatwhichamoleculeofwaterpassesthroughthecycleisnotrandombutisameasureoftherelativesizeofthevariousreservoirs.Ifwedefineresidencetimeastheaveragetimeforawatermoleculetopassthroughoneofthethreereservoirs—atmosphere,continent,andocean—weseethatthetimesareverydifferent.Awatermoleculestays,onanaverage,elevendaysintheatmosphere,onehundredyearsonacontinentandfortythousandyearsintheocean.Thislastfigureshowstheimportanceoftheoceanastheprincipalreservoirofthehydrospherebutalsotherapidityofwatertransportonthecontinents.Avastchemicalseparationprocesstakesplacesduringtheflowofwateroverthecontinents.Solubleionssuchascalcium,sodium,potassium,andsomemagnesiumaredissolvedandtransported.Insolubleionssuchasaluminum,iron,andsiliconstaywheretheyareandformthethin,fertileskinofsoilonwhichvegetationcangrow.Sometimessoilsaredestroyedandtransportedmechanicallyduringflooding.Theerosionofthecontinentsthusresultsfromtwocloselylinkedandinterdependentprocesses,chemicalerosionandmechanicalerosion.Theirrespectiveinteractionsandefficiencydependondifferentfactors.6.Accordingtothepassage,cloudsareprimarilyformedbywater______.AprecipitatingontothegroundBchangingfromasolidtoaliquidstateCevaporatingfromtheoceansDbeingcarriedbywind7.Thepassagesuggeststhatthepurposeofthehydrographicnetworkisto______.AdeterminethesizeofmoleculesofwaterBpreventsoilerosioncausedbyfloodingCmovewaterfromtheEarth'ssurfacetotheoceansDregulatetherateofwaterflowfromstreamsandrivers8.Whatdeterminestherateatwhichamoleculeofwatermovesthroughthecycle,asdiscussedinthethirdparagraph?AThepotentialenergycontainedinwater.BTheeffectsofatmosphericpressureonchemicalcompounds.CTheamountsofrainfallthatfallonthecontinents.DTherelativesizeofthewaterstorageareas.9.Allofthefollowingareex