一道英语阅读题：Theword“colossal”inLine3mostlikelymeans________.Computersmayonedayturnnightintoday—withgoodold,naturalsunlight.Colossalcomputer-controlledmirrors,thousandsoffeetacross,mayonedayorbittheearth,

　　一道英语阅读题：Theword“colossal”inLine3mostlikelymeans________.

　　Computersmayonedayturnnightintoday—withgoodold,naturalsunlight.

　　Colossalcomputer-controlledmirrors,thousandsoffeetacross,mayonedayorbittheearth,reflectingsunlightontoadarkenedUnitedStates.

　　SomeScientistssaythat16ofthesemirrors,eachaboutahalfmileacross,couldaimtheirreflectedlightatoneareaontheearththatwasabout200milesby300miles.Thatmuchlightwouldequalabout56moons.

　　Themirrorswouldbesohighthattheycouldcatchthesun’slightasitwasshiningontheothersideoftheearth.Themirrorscouldorbit—thousandsofmileshigh—atthesamespeedastheearthturnsonitsaxis(轴).Thatway,the

　　mirrorswouldalwaysbeoverthesamespot.

　　Thealuminum-coated(涂铝的),plasticmirrorscouldbefoldedupandpackedintoaspaceship,accordingtothescientists.Oncereleasedafewhundredmilesinspace,themirrors,poweredbyasolar-poweredengine,couldmarktherestofthetripintospaceontheirown.

　　Thescientistssaythatthecomputer-controlledmirrorscouldalsobemadetotilt(倾斜)slowly,sothereflectedsunlightwouldsweepslowlyalongthesurfaceoftheearth.Forexample,asnightfell,themirrorscouldbetiltedtolightupBoston.Lateron,asdarknessspreadslowlywestward.Chicago,forexample,thenSanFranciscocouldbelitup.Thereflectedsunlightwouldallowthesecitiestosaveupelectricity.Andinemergencies,suchaspower-failures,themirrorscouldlightuptheaffectedarea.

　　Whatnooneknowsyetiswhateffectthisartificialdaytimewouldhaveonplants,animals,andhumans.Woulditconfusesomeanimalsandharmplantsthatareusedtoregularday-nightcycles?Thescientistsrecommendthatstudiesbedonetofindoutwhathadeffectstheremightbe.

　　Theword“colossal”inLine3mostlikelymeans________.

　　A)nuclear-powered

　　B)orbiting

　　C)giant

　　D)spinning（D）

　　为什么选D啊?