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  Theideaofbeingabletowalkonwaterhaslonginterestedhumansgreatly.Sadlybiologicalfactspreventuseveraccomplishingsuchathingwithoutartificialaid---wesimplyweightoomuchandallourmasspushesdownthroughourrelat

  Theideaofbeingabletowalkonwaterhaslonginterestedhumansgreatly.Sadlybiologicalfactspreventuseveraccomplishingsuchathingwithoutartificialaid---wesimplyweightoomuchandallourmasspushesdownthroughourrelativelysmallfeetresultinginalotofpressurethatmakesussink.

  Howeverseveraltypesofanimalscanwalkonwater.OneofthemostinterestingisthecommonbasiliskBasilicusbasilicusalizard(蜥蜴)nativetoCentralandSouthAmerica.Itcanrunacrosswaterforadistanceofseveralmetersavoidinggettingwetbyrapidlyhittingthewater’ssurfacewithitsfeet.Thelizardwilltakeasmanyas20stepspersecondtokeepmovingforward.Forhumanstodothiswe’llneedhugefeetthatwecouldbringuptoourearsinordertocreateadequate“hitting.”

  Butfortunatelythereisanalternative:cornflour.Byaddingenoughofthiscommonthickeningagenttowater(anditdoestakealot)youcancreatea“non-Newtonian”liquidthatdoesn’tbehavelikenormalwater.Nowifthesurfaceofthewaterishithardenoughparticles(粒子)inthewatergrouptogetherforamomenttomakethesurfacehard.Movequicklyenoughandputenoughforceintoeachstepandyoureallycanwalkacrossthesurfaceofanadequatelythickliquidofcornflour.

  Funthoughallthismaysoundit’sstillrathermessyandbetterreadaboutintheorythancarriedoutinpractice.Ifyoumustdoitthenkeepthewaterwingshandyincaseyoustarttosink---andtakeashowerafterward!

  【小题1】Walkingonwaterhasn’tbecomearealitymainlybecausehumans_______.

  A.arenotinterestedinitB.havebiologicallimitationsC.havenotinventedpropertoolsD.areafraidtomakeanattempt【小题2】WhatdoweknowaboutBasilicusbasilicasfromthepassage?A.Itislightenoughtowalkonwater.B.Itshugefeetenableittostayabovewater.C.ItcanrunacrosswateratacertainspeedD.Itsuniqueskinkeepsitfromgettingwetinwater【小题3】Whatisthefunctionofthecornflouraccordingtothepassage?A.Tocreateathickliquid.B.Toturnthewaterintos

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2020-11-0220:33
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马智亮

  【小题1】B【小题2】C【小题3】A【小题4】D解析分析:人类有一个一直感兴趣但一直未能实现的愿望:水上行走。不能实现的原因是“生物性局限”。本文主要介绍了一种理论上可行实际上难以实现的人类水上行走...

2020-11-02 20:35:39
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