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ID:15418664
大小:390.50 KB
页数:17页
时间:2018-08-03
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1、新编大学英语四级考试模拟试卷(一)PartⅠWriting(30minutes)Directions:Forthispart,youareallowed30minutestowriteashortessayentitledUniversityStudentsShouldBeEncouragedtoPayTheirTuition.Youshouldwriteatleast120wordsfollowingtheoutlinegivenbelow:1.大学生的学费大多由家长支付2.有人认为应该鼓励大学生自付学费3.你的观点注意:此部分试题在答题卡1上。PartIIRe
2、adingComprehension(SkimmingandScanning)(15minutes)Directions:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.Forquestions1-7,markY(forYES)ifthestatementagreeswiththeinformationgiveninthepassage;N(forNO)ifthestatementcontradictstheinformation
3、giveninthepassage;NG(forNOTGIVEN)iftheinformationisnotgiveninthepassage.Forquestions8-10,completethesentenceswiththeinformationgiveninthepassage.WirelessPowerScientistshavetriedtodevelopmethodsofwirelesspowertransmissionthatcouldcuttheclutterorleadtocleansourcesofelectricity.Whilethei
4、deamaysoundfuturistic,itisn'tparticularlynew.NicolaTeslaproposedtheoriesofwirelesspowertransmissioninthelate1800sandearly1900s.OneofhismorespectaculardisplaysinvolvedremotelypoweringlightsinthegroundathisColoradoSpringsexperimentstation.Tesla'sworkwasimpressive,butitdidn'timmediatelyl
5、eadtowidespread,practicalmethodsforwirelesspowertransmission.Sincethen,researchershavedevelopedseveraltechniquesformovingelectricityoverlongdistanceswithoutwires.Someexistonlyastheoriesorprototypes,butothersarealreadyinuse.Ifyouhaveanelectrictoothbrush,forexample,youprobablytakeadvant
6、ageofonemethodeveryday.Atoothbrush'sdailyexposuretowatermakesatraditionalplug-inchargerpotentiallydangerous.Ordinaryelectricalconnectionscouldalsoallowwatertoseepintothetoothbrush,damagingitscomponents.Becauseofthis,mosttoothbrushesrechargethroughinductivecoupling.Inductivecouplinguse
7、smagneticfieldsthatareanaturalpartofcurrent'smovementthroughwire.Anytimeelectricalcurrentmovesthroughawire,itcreatesacircularmagneticfieldaroundthewire.Bendingthewireintoacoilamplifiesthemagneticfield.Themoreloopsthecoilmakes,thebiggerthefieldwillbe.Ifyouplaceasecondcoilofwireinthemag
8、netic
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