阅读下列四篇短文，从每小题后所给的A,B,C或D四个选项中，选出最佳选项。ATrainFloatingOnAirAtrainthatfloatsonair?It’snotmagic—it’smagnets(磁).Andit’sclosetoreality.InVirginiaUSAthefallof2002,atrainwithnowheelstraveledonairandcarriedcollegestudentsacrosstheircampus.InJapan,awhisper-quietrailwayenginehoveredandracedat350milesperhourusingmagnetsandelectricityasthepower.AndinChina,amagnettrainlinelinkedShanghaiwithnearbyPudongAirport.Thesetrainsusemagneticlevitation(悬浮)technology,“maglev”forshort.Theyusethesamerulesasthemagnetsyoupickupathomeorschool:oppositepolesofmagnetsattracteachother,andlikepolesrepeleachother.Howdoesitwork?Powerfulmagnetsonthebottomofthetrainrepelmagnetsonthetrack,whichisactuallyjustamagnet-filledguidingway.Withamagneticfieldofsufficientforce,thetrainwillgohoveringonair,whichseemedimpossibletousinthepast.Whenanelectricalcurrentissentthroughthetrack,thetrainmoves.Turnthecurrentbackwardsandthetrainslowsdown.Maglevdoesn’trelyonthefriction(摩擦力)ofwheelsontrack,soitcanclimbamuchsteeperhillthanatraditionaltrain.Anditcantraveleasilyinsnowandice,somethingthatcouldbringnormaltrainstoascreamingstop.1.Thispassageisabout.A.maglevB.magnetsC.levitationD.electricity2.Whichofthefollowingisarepellingaction?A.⇨⇦B.⇦⇨C.⇧⇧D.⇩⇩3.Whatcanwelearnfromthetext?A.Amagnet-filledguidingwayisformedinsideamaglevtrain.B.Insteadofelectricity,magnetsareusedasthepowerofamaglev.C.Maglevtrainscanclimbhillswiththehelpofmagnetwheels.D.Electriccurrentsdecidethemovementsofamaglevtrain.4.Whatisthedifferencebetweenamaglevtrainandanordinarytrain?A.Amaglevtraincanclimbmountainswithoutpowerwhileanordinaryonecan’t.B.Amaglevtraincantravelincollegecampuswhileanordinarytrainisnotallowed.C.Travelingwithoutatrack,amaglevtrainissaferandsmootherthananordinaryone.D.Floatingonatrack,amaglevtrainisfaster,quieterthananordinaryrailwaytrain.【参考答案】1—4、ABDD阅读理解。WeexperiencedifferentformsoftheSun’senergyeveryday.Wecanseeitslightandfeelitswarmth.TheSunisthemajorsourceofevaporation(蒸发)ofwaterfromtheoceansandlakes.Sunlighta