专题22科普类说明文阅读理解(2010﹒安徽﹒阅读理解B)Haveyoueverwondered?1.Whydoairplanestakelongertoflywestthaneast?Itcantakefivehourstogowest-eastfromNewYork(NY)toLondonbursevenhourstotraveleast-westfromLondontoNY.Thereasonforthedifferenceisanatmosphericphenomenonknownasthejet(喷射)stream.ThejetstreamisaveryhighaltitudewindwhichalwaysblowsfromthewesttotheeastacrosstheAtlantic.Theplanesmovingataconstantairspeedthusgofasterinthewest-eastdirectionwhentheyaremovingwiththewindthanintheoppositedirection.2.WhatwouldhappenifthegravityonEarthwassuddenlyturnedoff?Supposingwecouldmagicallyturnoffgravity.Wouldbuildingsandotherstructures(建筑物)floataway?WhathappenedwoulddependonhowstronglythethingswereattachedtotheEarth.TheEarthismovingatquiteaspeed,movingatoverathousandmilesperhours.Ifyouturnsomethingaroundyourheadonastring（细绳）,itgoesaroundinacircleuntilyouletgoofthestring.Thenitfliesoffinastraightline.‘Switchingoff’gravitywouldbelikelettinggoofthestring.ThingsnotattachedtotheEarthwouldflyoffinastraightline.Peopleinbuildingswouldsuddenlyshootupwardsatagreatspeeduntiltheyhittheceiling.Mostthingsoutsidewouldflyoffintospace.60.Whatinformationcanwegetfromthefirstpassage?A.ItisjetstreamthataffectshowfastairplanesflyB.PlanesgoslowerwhentheyaremovingwiththewindC.IttakesmoretimetoflyfromNYtoLondonthanfromLondontoNYD.TheyetstreamalwaysblowsfromtheeasttothewestacrosstheAtlantic61.Theword”shoot”underlineinthe2ndpassageprobablymeans“”A.sendforB.movequicklyC.comeoutD.grrowquickly第1页/共176页62.Itcanbeinferredthatwithoutgravity.A.buildingsandotherstructureswouldfloatawayB.treesandbuildingswouldnoteasilyflyoffC.somethingaroundyourheadwouldnotflyawayD.everythingoutsidebuildingswouldflyoffintospace63.WherecanwemostprobablyreadinthetextA.InareseachpaperB.InashortstoryC.InatravelmagazineD.Inastudent’sbook【解析】本文是科普说明文，主要介绍了飞机为什么向西面飞比向东面飞花的时间更长的原因是气流的方向．从纽约飞往伦敦要花5个小时，而从伦敦飞往纽约则要花7小时．花费时间不同的原因大气现象，...
