人教版英语必修五课文电子版Word文档格式.docx

人教版英语必修五课文电子版Word文档格式.docx

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UnitlGREATSCIENTISTS@#@JOHNSNOWDEFEATS“KINGCHOLERA,,@#@JohnSnowwasafamousdoctorinLondon—soexpert,indeed,thatheattendedQueenVictoriaasherpersonalphysician.Buthebecameinspiredwhenhethoughtabouthelpingordinarypeopleexposedtocholera.Thiswasthedeadlydiseaseofitsday.Neitheritscausenoritscurewasunderstood.Somanythousandsofterrifiedpeoplediedeverytimetherewasanoutbreak.JohnSnowwantedtofacethechallengeandsolvethisproblem.Heknewthatcholerawouldneverbecontrolleduntilitscausewasfound.@#@Hebecameinterestedintwotheoriesthatpossiblyexplainedhowcholerakilledpeople.Thefirstsuggestedthatcholeramultipliedintheair,acloudofdangerousgasfloatedarounduntilitfounditsvictims.Fromthestomachthediseasequicklyattackedthebodyandsoontheaffectedpersondied.@#@JohnSnowsuspectedthatthesecondtheorywascorrectbutheneededevidence.SowhenanotheroutbreakhitLondonin1854,hewasreadytobeginhisenquiry.Asthediseasespreadquicklythroughpoorneighbourhoods,hebegantogatherinformation.Intwoparticularstreets,thecholeraoutbreakwassoseverethatmorethan500peoplediedintendays.Hewasdeterminedtofindoutwhy.@#@Firsthemarkedonamaptheexactplaceswhereallthedeadpeoplehavelived.Thisgavehimavaluableclueaboutthecauseofthedisease.ManyofthedeathswerenearthewaterpumpinBroadStreet（especiallynumbers163738and40）.Healsonoticedthatsomehouses（suchas20and21BroadStreetand8and9CambridgeStreet）hadhadnodeaths.Hehadnotforeseenthis,sohemadefurtherinvestigations.Hediscoveredthatthesepeopleworkedinthepubat7CambridgeStreet.Theyhadbeengivenfreebeerandsohadnotdrunkthewaterfromthepump.Itseemedthatthewaterwastoblame.@#@Next,JohnSnowlookedintothesourceofthewaterforthesetwostreets.HefoundthatitcamefromtheriverpollutedbythedirtywaterfromLondon.HeimmediatelytoldtheastonishedpeopleinBroadStreettoremovethehandlefromthepumpsothatitcouldnotbeused.Soonaftenvardsthediseasesloweddown.Hehadshownthatcholerawasspreadbygennsandnotinacloudofgas.@#@InanotherpartofLondon,hefoundsupportingevidencefromtwootherdeathsthatwerelinkedtotheBroadStreetoutbreak.Awoman,whohadmovedawayfromBroadStreet,likedthewaterfromthepumpsomuchthatshehaditdeliveredtoherhouseeveryday.Bothsheandherdaughterdiedofcholeraafterdrinkingthewater.WiththisextraevidenceJohnSnowwasabletoannouncewithcertaintythatpollutedwatercarriedthevirus.@#@Topreventthisfromhappeningagain,JohnSnowsuggestedthatthesourceofallthewatersuppliesbeexamined.Thewatercompanieswereinstructednottoexposepeopletopollutedwateranymore.Finally"@#@KingCholera,,wasdefeated.@#@COPERNICUS,REVOLUTIONAYTHEORY@#@NicolausCopernicuswasfrightenedandhismindwasconfused.Althoughhehadtriedtoignorethem,allhismathematicalcalculationsledtothesameconclusion:

@#@thattheearthwasnotthecentreofthesolarsystem.Onlyifyouputthesuntheredidthemovementsoftheotherplanetsintheskymakesense.YethecouldnottellanyoneabouthistheoryasthepowerfulChristianChurchwouldhavepunishedhimforevensuggestingsuchanidea.TheybelievedGodhadmadetheworldandforthatreasontheearthwasspecialandmustbethecentreofthesolarsystem.@#@Theproblemarosebecauseastronomershadnoticedthatsomeplanetsintheskyseemedtostop,movebackwardandthengoforwardinaloop.Othersappearedbrighterattimesandlessbrightatothers.Thiswasverystrangeiftheearthwasthecentreofthesolarsystemandallplanetswentaroundit.@#@Copernicushadthoughtlongandhardabouttheseproblemsandtriedtofindananswer.Hehadcollectedobservationsofthestarsandusedallhismathematicalknowledgetoexplainthem.Butonlynewtheorycoulddothat.Sobehveen1510and1514heworkedonit,graduallyimprovinghistheoryuntilhefeltitwascomplete.@#@In1514heshoweditprivatelytohisfriends.Thechangeshemadetotheoldtheorywererevolutionary.Heplacedafixedsunatthecentreofthesolarsystemwiththeplanetsgoingrounditandonlythemoonstillgoingaroundtheearth.Healsosuggestedthattheearthwasspinningasitwentaroundthesunandthisexplainedchangesinthemovementoftheplanetsandinthebrightnessofthestars.Hisfriendswereenthusiasticandencouragedhimtopublishhisideas,butCopernicuswascautious.HedidnotwanttobeattackedbytheChristianChurch,soheonlypublisheditashelaydyingin1543.@#@Certainlyhewasrighttobecareful.TheChristianChurchrejectedhistheory,sayingitwasagainstGod'@#@sideaandpeoplewhosupporteditwouldbeattacked.YetCopernicus'@#@theoryisnowthebasisonwhichallourid