2017职称英语考试备考辅导综合类C级一

2017职称英语考试备考辅导综合类C级一MaglevTrains1Afewcountriesareusingpowerfulelectromagnetstodevelophigh-speedtrains,calledmaglevtrains.Maglevisshortformagneticlevitation1,whichmeansthatthesetrainsfloatoveraguidewayusingthebasicprinciplesofmagnetstoreplacetheoldsteelwheelandtracktrains.2Ifyou’veeverplayedwithmagnets,youknowthatoppositepolesattractandlikepolesrepeleachother2.Thisisthebasicprinciplebehindelectromagneticpropulsion.Electromagnetsaresimilartoothermagnetsinthattheyattractmetalobjects,butthemagneticpullistemporary.YoucaneasilycreateasmallelectromagnetyourselfbyconnectingtheendsofacopperwiretothepositiveandnegativeendsofanAA-cellbattery3.Thiscreatesasmallmagneticfield.Ifyoudisconnecteitherendofthewirefromthebattery,themagneticfieldistakenaway.3Themagneticfieldcreatedinthiswire-and-batteryexperimentisthesimpleideabehindamaglevtrainrailsystem.Therearethreecomponentstothissystem:Alargeelectricalpowersource,metalcoilsliningaguidewayortrack,andlargeguidancemagnetsattachedtotheundersideofthetrain.4Thebigdifferencebetweenamaglevtrainandaconventionaltrainisthatmaglevtrainsdonothaveanengine—atleastnotthekindofengineusedtopulltypicaltraincarsalongsteeltracks4.Theengineformaglevtrainsisratherinnoticeable.Insteadofusingfossilfuels,themagneticfieldcreatedbytheelectrifiedcoilsintheguidewaywallsandthetrackcombinestopropelthetrains5.5Themagnetizedcoilrunningalongthetrack,calledaguideway,repelsthelargemagnetsonthetrain’sundercarriage,allowingthetraintolevitatebetween1to10cmabovetheguideway.Oncethetrainislevitated,powerissuppliedtothecoilswithintheguidewaywallstocreateauniquesystemofmagneticfieldsthatpullandpushthetrainalongtheguideway.Theelectriccurrentsuppliedtothecoilsintheguidewaywallsisconstantlyalternatingtochangethepolarityofthemagnetizedcoils.Thischangeinpolaritycausesthemagneticfieldinfrontofthetraintopullthevehicleforward,whilethemagneticfieldbehindthetrainaddsmoreforwardthrust.6Maglevtrainsfloatonacushionofair,eliminatingfriction.Thislackoffrictionallowsthesetrainstoreachunprecedentedgroundtransportationspeedsofmorethan500kph,ortwiceasfastasthefastestconventionaltrain.At500kph,youcouldtravelfromParistoRomeinjustovertwohours.词汇：levitate/5leviteit/v.悬浮line/lain/v.排列成行electrified/I5lektrIfaI/v.使带电propel/prE5pel/vt.推进levitation/7levi5teiFEn/n.悬浮underside/5QndEsaid/n.下侧，下面magnetize/5mA^nItaIz/v.使带磁propulsion/prE5pQlFEn/n.推进guideway/5^aidwei/n.导向槽undercarriage/5QndE7kAridV/n.车盘注释:1.Maglevisshortformagneticlevitation:maglev是magneticlevitation的缩略词。2.oppositepolesattractandlikepolesrepeleachother:异极相吸，同极相斥3.AA-cellbattery：5号电池4.atleastnotthekindofengineusedtopulltypicaltraincarsalongsteeltracks:至少不是沿着轨道拉动典型的火车车厢的那种发动机。5.themagneticfieldcreatedbytheelectrifiedcoilsintheguidewaywallsandthetrackcombinetopropelthetrain:由嵌入导向壁内的电磁线圈产生的磁场加上轨道，一起推动火车前进。Themagneticfield和thetrack是句子主语，createdbytheelectrifiedcoilsintheguidewaywalls是过去分词短语，用作定语，修饰themagneticfield.练习:1.Paragraph3ATheMainComponentsoftheMaglevTrainSystem2.Paragraph4BCHigh-speedMaglevduetoZeroFrictionTheWorkingPrincipleoftheMaglevTrain3.Paragraph5DDifferencesbetweenPolarityandMagneticField4.Paragraph6EFComparisonofMaglevTrainswithTraditionalOnesMaglevwithaPowerfulMotor5.Severalcountriesintheworldareusingstrongelectromagnets6.Youcanconnectawiretothepositiveandnegativeendsofabattery7.Auniquesystemofmagneticfieldsiscreatedbythecoils8.ThefrictionlessmaglevtrainenablesyouAtodevelopamaglevtrainrailsystemBtoexplainwhymaglevtrainsarefasterCtopullandpushthetrainforwardDtocreateamagneticfieldEtoexperimentwiththemaglevtrainFtotravelfromParistoRomeinabouttwohours答案与题解：1.A第三段了举了磁浮列车的三个组成部分，动力源、金属线圈和此贴。选项A概括了第三段列的内容。2.E第四段就磁浮列车和传统火车进行了比较：磁浮列车没有发动机而传统火车有发动机。选项E用comparsion来概括是准确的。3.C第五段比较详细的介绍了为什么磁浮列车会向前运动，也就揭示了磁浮列车的工作原理。4.B在第五段解释了磁浮列车浮起和向前运动的原理之后，作者在第六段中进行了磁浮列车速度奇快的原因：去除了传统火车的车轮于铁轨的摩擦。5.A选A的依据是本文第一段第一句：Afewcountriesusingpowerfulelectromagnetstodevelophigh-speedtrains,calledmaglevtrains.6.D第二段说，把电线与干电池相连接就能产生一个小磁场，而磁浮列车的运动原理与此相同。第二段第四句是选择D