职称英语等级考试理工AB精讲班课程(17)第十七讲阅读理解

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1、职称英语等级考试理工AB精讲班课程第十七讲阅读理解>008年职称英语词汇大纲新增内容（14）:2008年《职称英语等级考试大纲》上首字母为U的新增单词C级uncivilizedadj.不开化的，落后的civilizedadj.文明的，开化的underlievt.成为…的基础A级unscrupulousadj.不择手段的unscrupulously-byfairmeansorfoul-byallkindsofmeans-byhook不择手段地>阅读理解例题解析：WhyHumansWalkOnTwoLegsAteamofscientiststhatstudiedchimpanzeestraincd

2、tousetreadmi1Ishasgatherednewevidencesuggestingthatourearliestapelikeancestorsstartedwalkingontwolegsbecauseitrequiredlessenergythangettingaroundonallfours.“Whenourearliestancestorsstartedwalkingontwolegs,theytookthefirststepstowardbecominghuman,”saidleadresearcherMichaelSockolofUCDavis1.“Ourfinding

3、shelpanswerwhy.”Sockolworkedfortwoyearstofindananimaltrainerwi1lingtocoaxadultchimpstowalkontwolegsandto"knucklewalk”onallfoursonthesortoftreadmillfoundinmostgyms.Thefivechimpsalsoworefacemasksusedtohelptheresearchersmeasureoxygenconsumption.Whilethechimpsworkedout,thescientistscollectedmetabolicand

4、otherdatathatallowedthemtocalculatewhichmethodoflocomotionusedlessenergyandwhy.Thetearngatheredthesameinformationforfouradulthumanswalkingonatreadmill.Theresearchersfoundthathumanwalkingusedabout75percentlessenergyandburned75percentfewercaloriesthanquadrupedalandbipedal2walkinginchimpanzees-Theyalso

5、foundthatforsomebutnotallofthechimps,walkingontwolegswasnomorecostlythanknucklewalking・aWewerepreparedtofindthatal1ofthechimpsusedmoreenergywalkingontwolegs-butthatfinclingwouldn^thavebeenasinteresting,”Sockolsaid.uWhatwefoundwasmuchmoretelling.Forthreechimps,bipedalismwasmoreexpensive,butfortheothe

6、rtwochimps,thiswasn"tthecase.Onespentaboutthesameenergywalkingontwolegsasonfour.Theotherusedlessenergywalkingupright.”Thesetwochimpshaddifferentgaitsandanatomythantheirknucklewalkingpeers.Takentogether,thefindingsprovidesupportforthehypothesisthatanatomicaldifferencesaffectinggaitexistedamongourearl

7、iestapelikeancestors,andthatthesedifferencesprovidedthegeneticvariationwhichnaturalselectioncouldactonwhenchangesintheenvironmentgavebipedsanadvantageoverquadrupeds.Fossilandmolecularevidencesuggestst