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第PAGE\*MERGEFORMAT3页共NUMPAGES\*MERGEFORMAT3页 2021年英语六级改错冲刺训练(8) Somepeople,inallseriousness,saythathumanswillbelivinginspacewithinthenexthundredorsoyears.PlanetEarthwillbecrowded,dirtyandlackofresources.Asortofexodus--71.ofmankindwillbegin.Spaceshipswillbeassembledsothattheyrevolvearoundtheearth.SomemayorbitaroundMars.Thesespacestationswillbeservicedbyspacebuses.Wesawthefirstspacebuslaunchin--72.April1981.Thiswas"Columbia",itmadeseveral--73.orbitsaroundtheearthandthenreturned,landingonahugedrylakebedinCalifornia."Columbia"willbeusedagain.Previousspaceshipshavebeenabandoned,onlythenoseconebeingusedtobringthecrewsbacktoearth.--74.Uponestablished,eachspacestationwill--75.generateitsownatmosphereandhaveitsownagriculture.Itwillneedtorotationtoprovide--76.anartificialgravity;peoplewillbeforcedinwards--77.fromthecenterbycentrifugalforce.ThemoonandMarscouldbecomenewsourcesofnewmaterials.Drivingthroughspacewillno--78.longerneedEarthfuel-theenergywouldcomefromthesun.Thisenergywouldbeconvertedfrom--79.electricitytoworkmagneticrockets.Thatallsoundsquitefantasticallybut,with--80.therapiddevelopmentofmodernstechnology,whoknowsaboutwhatthefutureholds?71.lack--short72.launch--launched73.it--which74.crews--crew75.upon--once76.rotation--rotate77.inwards-outwards78.will--would79.from--into80.fantastically--fantastic
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