四川省学位英语考试

everses.Theclockstick64,andyoungadultsbegintogotosleepandwakeupearlierandearlier.Eventually,theirclockscoincidewith65ofolderpeople.Thequickchangemaymarkthebiologicalendofteenageyears.Adifference66thetiminginmenandinwomenpointstoabiologicalcause,perhapsahormonaleffect.Becausethelivingclockis67byexposuretosunlight,theresearcherssuspectsthemanyhourssomekids68stayingintheirdarkroomscouldpushtheclocksevenlater—moninindustrializedsocieties.Theresearchersalsodiscoveredthatruralresidents,69lifestyleputsthemindaylightmore,retireandriseanhourearlierthancity70.“Wethinkthisisonlythetipofanicebergthatshowsustheconsequencesofdim-lightenvironments,”theresearcherssay.61.A.formerB.latterC.firstD.last62.A.rangeB.rangesC.rangingD.ranged63.A.RatherB.ThoughC.YetD.Nevertheless64.A.forthB.forwardsC.upwardsD.back