Naturaldisasters当地震、火灾、沙尘暴、龙卷风等自然灾害发生时，人类才真正意识到，面对强大的自然威力，我们是多么的脆弱！Notmanyofushaveexperiencedanaturaldisasterlikeatornado.HowwouldwecopeinHurricaneCharleywhichhitFloridaintheUSAin2004?Inthewestcoastareas,800,000peoplewereevacuatedtoescapewindswhichreachednearly140milesperhour.Somepeoplerefusedtoleavetheirhomes.Theyfilledthebathtubwithwater,putsandbagsagainstthewindows,broughteverythinginsideandboardeduptheirwindows.Onemanwassittinginhiskitchenwhenthemicrowaveovenflewacrosstheroom.Histrailerhome(旅行用活动住屋)wasdestroyedandwhenhewalkeddowntheroadtothehospital,hediscoveredthatitwasalsoverydamagedbythewinds.Atonenursingcenter,roofswererippedoff,windowsshatteredanddoorspulledopen.Everyoneremainedsurprisinglycalmunderthecircumstances.Overahundredsheltersweresetuptohelpthoseinneed.Atoneofthesecenterswhichheld100,000people,theroofwasrippedoff.TheUSGovernmentprovided120tonsoffoodfor250,000mealstobeginwithandbuiltabasecampwith500showerunitstohelpthestrandedfamilies.InsurancecompaniesexpecttopayoutapproximatelyUS＄7.4billiontorepairthedamage.TornadoesareclassifiedusingtheFujitaScale.ThisgivesratingsfromF0toF5.Thesystemestimatesthelengthofthetornadoandthewidthofitspath.Sometimesverylargetornadoesareweakandsmallonesextremelyviolent.F0meanstheremightbesomedamagetochimneys,andshallowtreesmaybeuprooted.Thewindis72milesperhour,orgaleforce.AtF5thewindforceisdevastatingandmayreach260milesper用心爱心专心hour.Housescanbeleveledatthefoundationsandduringoneveryviolenttornado,sixvehicleswereseenintheairatonce.About1,000tornadoesarerecordedeachyearintheUSAandthereareprobablyafurther1,000mildertornadoeswhichgounrecorded.Inthepast,tornadoeswerealwaysasurpriseandmanyliveswerelostbecauseofthislackofknowledge.Today,theabilityofmeteorologiststounderstandweatherpatternssavesenormousnumbersoflives.用心爱心专心
