人教版高中英语必修五电子课本VIP免费

人教版高中英语必修五电子课本2————————————————————————————————作者：————————————————————————————————日期：按住Ctrl键单击鼠标打开配套教学视频名师讲课播放必修5Unit1JOHHSHOWDEFEATS“KINGCHOLERA”JohnSnowwasafamousdoctorinLondon-soexpert,indeed,thatheattendedQueenVictoriaasherpersonalphysician.Buthebecameinspiredwhenhethoughtabouthelpingordinarypeopleexposedtocholera.Thiswasthedeadlydiseaseofitsday.Neitheritscausenoritscurewasunderstood.Somanythousandsofterrifiedpeoplediedeverytimetherewasanoutbreak.JohnSnowwantedtofacethechallengeandsolvethisproblem.Heknewthatcholerawouldneverbecontrolleduntilitscausewasfound.Hebecameinterestedintwotheoriesthatpossiblyexplainedhowcholerakilledpeople.Thefirstsuggestedthatcholeramultipliedintheair.Acloudofdangerousgasfloatedarounduntilitfounditsvictims.Thesecondsuggestedthatpeopleabsorbedthisdiseaseintotheirbodieswiththeirmeals.Fromthestomachthediseasequicklyattackedthebodyandsoontheaffectedpersondied.JohnSnowsuspectedthatthesecondtheorywascorrectbutheneededevidence.SowhenanotheroutbreakhitLondonin1854,hewasreadytobeginhisenquiry.Asthediseasespreadquicklythroughpoorneighbourhoods,hebegantogatherinformation.Intwoparticularstreets,thecholeraoutbreakwassoseverethatmorethan500peoplediedintendays.Hewasdeterminedtofindoutwhy.Firsthemarkedonamaptheexactplaceswhereallthedeadpeoplehadlived.Thisgavehimavaluableclueaboutthecauseofthedisease.ManyofthedeathswerenearthewaterpumpinBroadStreet(especiallynumbers16,37,38and40).Healsonoticedthatsomehouses(suchas20and21BroadStreetand8and9CambridgeStreet)hadhadnodeaths.Hehadnotforeseenthis,sohemadefurtherinvestigations.Hediscoveredthatthesepeopleworkedinthepubat7CambridgeStreet.Theyhadbeengivenfreebeerandsohadnotdrunkthewaterfromthepump.Itseemedthatthewaterwastoblame.Next,JohnSnowlookedintothesourceofthewaterforthesetwostreets.HefoundthatitcamefromtheriverpollutedbythedirtywaterfromLondon.HeimmediatelytoldtheastonishedpeopleinBroadStreettoremovethehandlefromthepumpsothatitcouldnotbeused.Soonafterwardsthediseasesloweddown.Hehadshownthatcholerawasspreadbygermsandnotinacloudofgas.InanotherpartofLondon,hefoundsupportingevidencefromtwootherdeathsthatwerelinkedtotheBroadStreetoutbreak.Awoman,whohadmovedawayfromBroadStreet,likedthewaterfromthepumpsomuchthatshehaditdeliveredtoherhouseeveryday.Bothsheandherdaughterdiedofcholeraafterdrinkingthewater.WiththisextraevidenceJohnSnowwasabletoannouncewithcertaintythatpollutedwatercarriedthevirus.Topreventthisfromhappeningagain,JohnSnowsuggestedthatthesourceofallthewatersuppliesbeexamined.Thewatercompanieswereinstructednottoexposepeopletopollutedwateranymore.Finally"KingCholera"wasdefeated.COPERNICUS’REVOLUTIONRRYTHEORYNicolausCopernicuswasfrightenedandhismindwasconfused.Althoughhehadtriedtoignorethem,allhismathematicalcalculationsledtothesameconclusion:thattheearthwasnotthecentreofthesolarsystem.Onlyifyouputthesuntheredidthemovementsoftheotherplanetsintheskymakesense.YethecouldnottellanyoneabouthistheoryasthepowerfulChristianChurchwouldhavepunishedhimforevensuggestingsuchanidea.TheybelievedGodhadmadetheworldandforthatreasontheearthwasspecialandmustbethecentreofthesolarsystem.Theproblemarosebecauseastronomershadnoticedthatsomeplanetsintheskyseemedtostop,movebackwardandthengoforwardinaloop.Othersappearedbrighterattim...