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时间:2018-08-10
《2015年北师大考博英语真题试卷》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、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,m
2、iddle,andinner.Theouterearcollectssoundwavesanddirectsthemtotheeardrumseparatingtheouterearfromthemiddleear.Themiddleearconductssoundvibrationsthroughthreesmallbonestotheinnerear.Theinnerearisanetworkofchannelscontainingfluidthatmovesinresponsetosoundormovement.Toperformthefunctionofhe
3、aring,theearconvertstheenergyofpressurewavesmovingthroughtheairintonerveimpulsesthatmebrainperceivesassound.Vibratingobjects,suchasthevocalcordsofaspeakingperson,createwavesinmesurroundingair.Thesewavescausetheeardrumtovibratewiththesamefrequency.Thethreebonesofthemiddleearamplifyandtr
4、ansmitthevibrationstotheovalwindow,amembraneonthesurfaceofthecochlea,theorganofhearing.Vibrationsofmeovalwindowproducepressurewavesinthefluidinsidemecochlea.Haircellsinthecochleaconverttheenergyofthevibratingfluidintoimpulsesthattravelalongtheauditorynervetothebrain.Theorganforbalancei
5、salsolocatedintheinnerear.Sensationsrelatedtobodypositionaregeneratedmuchlikesensationsofsound.Haircellsintheinnerearrespondtochangesinheadpositionwithrespecttogravityandmovement.Gravityisalwayspullingdownonthehairs,sendingaconstantseriesofimpulsestothebrain.Whenthepositionoftheheadcha
6、nges—aswhentheheadbendsforward—theforceonthehaircellschangesitsoutputofnerveimpulses.Thebraintheninterpretsthesechangestodeterminethehead'snewposition.1.Whatcanbeinferredabouttheorgansforhearingandbalance?ABothorgansevolvedinhumansatthesametime.BBothorganssendnerveimpulsestothebrain.CB
7、othorganscontainthesameamountoffluid.DBothorgansarelocatedinmeear'smiddleregion.2.HearinginvolvesallofthefollowingEXCEPT______.AmotionofthevocalcordssothattheyvibrateBstimulationofhaircellsinfluid-filledchannelsCamplificationofsoundvibrationsDconversionofwaveenergyintonerveimpulses3.
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