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ID:10930593
大小:29.00 KB
页数:3页
时间:2018-07-09
《英语四六级口语练习推荐背诵文章(10)》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、46.VisionHumanvisionlikethatofotherprimateshasevolvedinanarborealenvironment.Inthedensecomplexworldofatropicalforest,itismoreimportanttoseewellthattodevelopanacutesenseofsmell.Inthecourseofevolutionmembersoftheprimatelinehaveacquiredlargeeyeswhilethesnouthasshrunktogivetheeyeanunimpededview.Ofmamma
2、lsonlyhumansandsomeprimatesenjoycolorvision.Theredflagisblacktothebull.Horsesliveinamonochromeworld.lightvisibletohumaneyeshoweveroccupiesonlyaverynarrowbandinthewholeelectromagneticspectrum.Ultravioletraysareinvisibletohumansthoughantsandhoneybeesaresensitivetothem.Humansthoughantsandhoneybeesares
3、ensitivetothem.Humanshavenodirectperceptionofinfraredraysunliketherattlesnakewhichhasreceptorstunedintowavelengthslongerthan0.7micron.Theworldwouldlookeerilydifferentifhumaneyesweresensitivetoinfraredradiation.Theninsteadofthedarknessofnight,wewouldbeabletomoveeasilyinastrangeshadowlessworldwhereob
4、jectsglowedwithvaryingdegreesofintensity.Buthumaneyesexcelinotherways.Theyareinfactremarkablydiscerningincolorgradation.Thecolorsensitivityofnormalhumanvisionisrarelysurpassedevenbysophisticatedtechnicaldevices.47FolkCulturesAfolkcultureisasmallisolated,cohesive,conservative,nearlyself-sufficientgr
5、oupthatishomogeneousincustomandracewithastrongfamilyorclanstructureandhighlydevelopedrituals.Orderismaintainedthroughsanctionsbasedinthereligionorfamilyandinterpersonal.Relationshipsarestrong.Traditionisparamount,andchangecomesinfrequentlyandslowly.Thereisrelativelylittledivisionoflaborintospeciali
6、zedduties.Rather,eachpersonisexpectedtoperformagreatvarietyoftasks,thoughdutiesmaydifferbetweenthesexes.Mostgoodsarehandmadeandsubsistenceeconomyprevails.Individualismisweaklydevelopedinfolkculturesasaresocialclasses.UnalteredfolkculturesnolongerexistinindustrializedcountriessuchastheUnitedStatesan
7、dCanada.PerhapsthenearestmodernequivalentinAngloAmericaistheAmish,aGermanAmericanfarmingsectthatlargelyrenouncestheproductsandlaborsavingdevicesoftheindustrialage.InAmishareas,horsedrawnbuggiesstillserveasa
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