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请选择请填写级别四级/六级试题编号托福提交日期2012年08月05日雅思YGRE/GMAT题型01Y/N/NG选材作者题目来源Rightandleft-handednessinhumans02选择题√03分类题04句子插入05配对题√篇幅924words06图表题07简答题题材关键词rightandleft-handedness;human;asymmetry;genetic;brain08填空题Rightandleft-handednessinhumans1.Whydohumans,virtuallyaloneamongallanimalspecies,displayadistinctleftorrighthandedness?Notevenourclosestrelativesamongtheapespossesssuchdecidedlateralasymmetry,aspsychologistscallit.Yetabout90percentofeveryhumanpopulationthathaseverlivedappearstohavebeenright-handed.ProfessorBryanTurneratDeakinUniversityhasstudiedtheresearchliteratureonleft-handednessandfoundthathandednessgoeswithsidedness.Sonineoutoftenpeopleareright-handedandeightareright-footed.Henotedthatthisdistinctiveasymmetryinthehumanpopulationisitselfsystematic.`Humansthinkincategories:blackandwhite,upanddown,leftandright.It'sasystemofsignsthatenablesustocategorisephenomenathatareessentiallyambiguous.'2.Researchhasshownthatthereisgeneticorinheritedelementtohandedness.Butwhileleft-handednesstendstoruninfamilies,neitherleftnorrighthanderswillautomaticallyproduceoff-springwiththesamehandedness;infactabout6percentofchildrenwithtworight-handedparentswillbeleft-handed.However,amongtwoleft-handedparents,perhaps40percentofthechildrenwillalsobeleft-handed.Withonerightandoneleft-handedparent,15to20percentoftheoffspringwillbeleft-handed.Evenamongidenticaltwinswhohaveexactlythesamegenes,oneinsixpairswilldifferintheirhandedness.3.Whatthenmakespeopleleft-handedifitisnotsimplygenetic?Otherfactorsmustbeatworkandresearchershaveturnedtothebrainforclues.Inthe1860stheFrenchsurgeonandanthropologist,DrPaulBroca,madetheremarkablefindingthatI.SurveyingtheText:1.Lookatthetitleandquicklygooverthebeginningparagraphanddecidethetopicofthepassage.Andthenreadtheconcludingparagraph,andtelltheauthor’sposition.Topic:Leftorright-handednessinhumans.(para.1)Position:Left-handersarealsogifted.Weshouldnotholdprejudiceonleft-handers.(para.6)2.Basedonthefirstsentenceonlyofeachparagraph,decidewhattheauthor’spurposeis.a.Toinformthescientificresearchonbrainevolution.b.Tocompareandcontrasttheadvantagesanddisadvantagesoftheleftorrighthandednessinhumans.c.Toproposesolutionstoleftorrighthandednessinhumans.d.Todiscussthedeterminingfactorsoftheleftorrighthandednessinhumans.3.Readparagraphs2-6,andtellwhatisthemainargumentofthepassage.Scientistshavefoundoutthatbraindevelopmentdecideswhetherapersonisaleftorright-hander.4.Readparagraph2-5againandsummarizehowthemainargumentissupported?Geneticorinheritedelementplaysaroleinhandedness.(para.2)Mostpeople,eitherleft-or-righthanded,havetheirlanguagecenterinthelefthemisphere.(para.3)Themajorityofpeopleareright-handedbecausetheleftsideofthebrainbecomesspecializedforthecontrolofmovement,includingspeech.(para.4)Thebrain,intheprocessofdevelopment,maybecomelesspatientswhohadlosttheirpowersofspeechasaresultofastroke(abloodclotinthebrain)hadparalysisoftherighthalfoftheirbody.Henotedthatsincethelefthemisphereofthebraincontrolstherighthalfofthebody,andviceversa,thebraindamagemusthavebeeninthebrain'slefthemisphere.Psychologistsnowbelievethatamongrighthandedpeople,probably95percenthavetheirlanguagecentreinthelefthemisphere,while5percenthaveright-sidedlanguage.Left-handers,however,donotshowthereversepatternbutinsteadamajorityalsohavetheirlanguageinthelefthemisphere.Some30percenthaverighthemispherelanguage.4.DrBrinkman,abrainresearcherattheAustralianNationalUniversityinCanberra,hassuggestedthatevolutionofspeechwentwithright-handedpreference.AccordingtoBrinkman,asthebrainevolved,onesidebecamespecialisedforfinecontrolofmovement(necessaryforproducingspeech)andalongwiththisevolutioncameright-handpreference.AccordingtoBrinkman,mostleft-handershavelefthemispheredominancebutalsosomecapacityintherighthemisphere.Shehasobservedthatifaleft-handedpersonisbrain-damagedinthelefthemisphere,therecoveryofspeechisquiteoftenbetterandthisisexplainedbythefactthatleft-handershaveamorebilateralspeechfunction.Inherstudiesofmacaquemonkeys,Brinkmanhasnoticedthatprimates(monkeys)seemtolearnahandpreferencefromtheirmotherinthefirstyearoflifebutthiscouldbeonehandortheother.Inhumans,however,thespecialisationinfunctionofthetwohemispheresresultsinanatomicaldifferences;areasthatareinvolvedwiththeproductionofspeechareusuallylargerontheleftsidethanontheright.Sincemonkeyshavenotacquiredthe1.Geneticorinheritedelementsplayaroleinhandedness.2.Thelefthemisphereisinchargeofthefinemovement,somostpeopleareright-handed.3.Somepeoplebecomeleft-handedbecausetheirbrainaresomewhataffectedintheprocessofdevelopment.III.Conclusion:Leftorright-handednessinhumansareonlyresultsofthebraindevelopmentinhumans.Right-handednessisnotalwaysbetterthanleft-handedness.artofspeech,onewouldnotexpecttoseesuchavariationbutBrinkmanclaimstohavediscoveredatrendinmonkeystowardstheasymmetrythatisevidentinthehumanbrain.5.TwoAmericanresearchers,GeschwindandGalaburda,studiedthebrainsofhumanembryosanddiscoveredthattheleft-rightasymmetryexistsbeforebirth.Butasthebraindevelops,anumberofthingscanaffectit.Everybrainisinitiall