2021年英语四级作文预测:冰箱的起源
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2021年英语四级作文预测:冰箱的起源思维导图模板大纲
TheOriginoftheRefrigerators
Bythemid-nineteenthcentury,thetermiceboxhadenteredtheAmericanlanguage,buticewasstillonlybeginningtoaffectthedietofordinarycitizensintheUnitedStates.Theicetradegrewwiththegrowthofcities.Icewasusedinhotels,taverns,andhospitals,andbysomeforward-lookingcitydealersinfreshmeat,freshfish,andbutter.
AftertheCivilWar(1861-1865),asicewasusedtorefrigeratefreightcars,italsocameintohouseholduse.Evenbefore1880halfoftheicesoldinNewYork,Philadelphia,andBaltimore,andone-thirdofthatsoldinBostonandChicago,wenttofamiliesfortheirownuse.
Thishadbecomepossiblebecauseanewhouseholdconvenience,theicebox,aprecursorofthemodernrefrigerator,hadbeeninvented.Makinganefficienticeboxwasnotaseasyaswemightnowsuppose.Intheearlynineteenthcentury,theknowledgeofthephysicsofheat,whichwasessentialtoascienceofrefrigeration,wasrudimentary.Thecommonsensenotionthatthebesticeboxwasonethatpreventedtheicefrommeltingwasofcoursemistaken,foritwasthemeltingoftheicethatperformedthecooling.
Nevertheless,earlyeffortstoeconomizeiceincludedwrappinguptheiceinblankets,whichkepttheicefromdoingitsjob.Notuntilneartheendofthenineteenthcenturydidinventorsachievethedelicatebalanceofinsulationandcirculationneededforanefficienticebox.Butasearlyas1803,aningeniousMarylandfarmer,ThomasMoore,hadbeenontherighttrack.Whenheusedaniceboxofhisowndesigntotransporthisbuttertomarket,hisbutter,stillfreshandhardinneat,wasworthone-poundabrick.Oneadvantageofhisicebox,Mooreexplained,wasthatfarmerswouldnolongerhavetotraveltomarketatnightinordertokeeptheirproducecool.
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