【英语阅读理解2Forcenturiesmanhaddreamedofachievingverticalflight.In400A.D.Chinesechildrenplayedwithafan-liketoythatspunupwards,andfellbacktoearthasrotationceased.LeonardodaVinciconceivedthefirstmechanicalapparatu】

　　英语阅读理解2

　　Forcenturiesmanhaddreamedofachievingverticalflight.In400A.D.Chinesechildrenplayedwithafan-liketoythatspunupwards,andfellbacktoearthasrotationceased.LeonardodaVinciconceivedthefirstmechanicalapparatus,called“Helix”,whichcouldcarryamanstraightupbutthiswasonlyadesignandnevertested.

　　Theancientdreamwasfinallyrealizedin1940whenaRussianimmigrant,anaeronauticalengineer,pilotedastrange-lookingcraftofsteeltubewitharotatingfanontop.Itroseawkwardlyandverticallyintotheairfromastandingstart,hoveredafewfeetabovetheground,wentsidewaysandbackwards,andthensettledbacktoearth.Thatvehiclewascalledahelicopter.

　　Imaginationswerefired.Mendreamedofcommutingtoworkintheirpersonalhelicopter.Everymanwouldhaveoneinhisbackyard.Peopleanticipatedthatverticalflighttransportswouldcarrymillionsofpassengersastheairlinesoftodaydo.Suchfantasticexpectationswerenotfulfilled.

　　Thehelicopterhasnowbecomeanextremelyversatilemachine.Itexcelsinmilitarymissions,carryingtroops,gunsandstrategicinstrumentstoplaceswhereotheraircraftscannotgo.Corporationsusethemasairborneoffices.Manymetropolitanareasusetheminpolicework,constructionandloggingcompaniesemploytheminvariousadvantageousways,

　　engineersusethemforsite-selectionandsurveying,andoilcompaniesusethemasthebestwaytomakeoffshoreandremoteworkstationsaccessibletocrewsandsupplies.Anyurgent

　　missiontoahard-to-get-toplaceislikelyataskforahelicopter.Amongtheirothermultitudeofuses,theydeliverpeopleacrosstown,flytoandfromairports,assistinrescuework,and

　　aidinthesearchformissingorwantedpersons.

　　11.Whatisahelicopter?

　　A.Anaircraftthatcangofasterthantheordinaryairplane.

　　B.Anaircraftthatfitsintothesmallestpossibleplace.

　　C.Anaircraftthatcanflyupvertically

　　D.Anaircraftthatisusedonlyforcommercialservice.

　　12.Whatissaidaboutthedevelopmentofthehelicopter?

　　A.Helicoptershaveonlybeenworkedonbymansince1940.

　　B.AnEnglishmanwasthefirsttoachieveflightin