雅思(阅读)模拟试卷54(题后含答案及解析).pdfVIP

雅思（阅读）模拟试卷54(题后含答案及解析)

题型有：1.ReadingModule

ReadingModule(60minutes)

Right-andleft-handednessinhumansWhydohumans,virtuallyalone

amongallanimalspecies,displayadistinctleftofright-handedness?Notevenour

closestrelativesamongtheapespossesssuchdecidedlateralasymmetry,as

psychologistscallit.Yetabout90percentofeveryhumanpopulationthathasever

livedappearstohavebeenright-handed.ProfessorBryanTurneratDeakinUniversity

hasstudiedtheresearchliteratureonleft-handednessandfoundthathandednessgoes

withsid-edness.Sonineoutofthepeopleareright-handedandeightareright-footed.

Henotedthatthisdistinctiveasymmetryinthehumanpopulationisitselfsystematic.

‘Humansthinkincategories:blackandwhite,upanddown,leftandright.It’sa

systemofsignsthatenablesustocategorisephenomenathatareessentially

ambiguous.Researchhasshownthatthereisageneticorinheritedelementto

handedness.Butwhileleft-handednesstendstoruninfamilies,neitherleftnorright

handerswillautomaticallyproduceoff-springwiththesamehandedness;infactabout

6percentofchildrenwithtworight-handedparentswillbeleft-handed.However,

amongtwoleft-handedparents,perhaps40percentofthechildrenwillalsobe

left-handed.Withonerightandoneleft-handedparent,15to20percentofthe

offspringwillbeleft-handed.Evenamongidenticaltwinswhohaveexactlythesame

genes,oneinsixpairswilldifferintheirhandedness.Whatthenmakespeople

left-handedifitisnotsimplygenetic?Otherfactorsmustbeatworkandresearchers

haveturnedtothebrainforclues.Inthe1860stheFrenchsurgeonandanthropologist,

DrPaulBroca,madetheremarkablefindingthatpatientswhohadl