职称英语等级考试理工AB精讲班课程17.doc

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1、大家论坛club.topsage.com职称英语等级考试理工AB精讲班课程第十七讲阅读理解Ø008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Ø阅读理解例题解析：WhyHumansWalkOnTwo

2、LegsAteamofscientiststhatstudiedchimpanzeestrainedtousetreadmillshasgatherednewevidencesuggestingthatourearliestapelikeancestorsstartedwalkingontwolegsbecauseitrequiredlessenergythangettingaroundonallfours.“Whenourearliestancestorsstartedwalkingontwolegs,theytookthefirsts

3、tepstowardbecominghuman,”saidleadresearcherMichaelSockolofUCDavis1.“Ourfindingshelpanswerwhy.”Sockolworkedfortwoyearstofindananimaltrainerwillingtocoaxadultchimpstowalkontwolegsandto“knucklewalk”onallfoursonthesortoftreadmillfoundinmostgyms.Thefivechimpsalsoworefacemasksu

4、sedtohelptheresearchersmeasureoxygenconsumption.Whilethechimpsworkedout,thescientistscollectedmetabolicandotherdatathatallowedthemtocalculatewhichmethodoflocomotionusedlessenergyandwhy.Theteamgatheredthesameinformationforfouradulthumanswalkingonatreadmill.Theresearchersfo

5、undthathumanwalkingusedabout75percentlessenergyandburned75percentfewercaloriesthanquadrupedalandbipedal2walkinginchimpanzees.Theyalsofoundthatforsomebutnotallofthechimps,walkingontwolegswasnomorecostlythanknucklewalking.“Wewerepreparedtofindthatallofthechimpsusedmoreenerg

6、ywalkingontwolegs–butthatfindingwouldn’thavebeenasinteresting,”Sockolsaid.“Whatwefoundwasmuchmoretelling.Forthreechimps,bipedalism3wasmoreexpensive,butfortheothertwochimps,thiswasn’tthecase.Onespentaboutthesameenergywalkingontwolegsasonfour.Theotherusedlessenergywalkingup

7、right.”Thesetwochimpshaddifferentgaitsandanatomythantheirknucklewalkingpeers.9大家论坛club.topsage.comTakentogether,thefindingsprovidesupportforthehypothesisthatanatomicaldifferencesaffectinggaitexistedamongourearliestapelikeancestors,andthatthesedifferencesprovidedthegenetic

8、variationwhichnaturalselectioncouldactonwhenchangesintheenvironmentgavebipedsanadvantageoverquad