Unit4Warmingup,Pre-reading&Listening(Wb)floodtyphoonearthquakevolcanodroughtnaturaldisastersfiresandstormHaveyougonethroughanynaturaldisaster?Whatdamagediditcause?Where?When?Howserious?typhoon,drought,earthquake,volcano,flood…Soitmaycausegreatdamagetoacitywhichsufferfromnaturaldisaster.TangshanandSanFrancisco,Discussion:Whatmighthappeniftherehasbeenabigearthquakeinthesetwocities?broadroadsbeautifulgardenstallbuildingslargepopulationPeoplelosetheirhomes.Manybuildingsaredestroyed.Roadsgethugecracks.Thebridgesfalldown.Steamburstfromholesintheground.Waterpipesaredestroyed.Therailwaytracksareuselesspiecesofsteel.Thewholecityliesinruins.Canweavoid(避免)orreduce(减少)thedamage?Wecanforetell(预测)earthquakes.Howtoforetellanearthquake?Whatmayhappenbeforeanearthquake?Let’slookatsomesigns(前兆).signs(前兆).1.Peopleseebrightlightsinthesky.2.Animalsaretoonervoustoeat.3.Micerunoutofthefieldsforplacestohide.Fishjumpoutofthepond.4.Thewellwallshavedeepcracksinthem.Howdoesanearthquakehappen?Whydoearthquakeshappen?Scientistsexplainthatthe______oftheearthismadeofanumberofdifferent________.AtSanFrancisco,thePacificplatewhichismovingtowardsthe______meetstheNorthAmericanplate.ThePacificplateismovingveryslowlyat____cmayear.Sometimesthesetwoplatesstopanddonotmoveforyears.Thensuddenly,they_______andanearthquakeis______.outsideplatesnorthwest5.3jumpfeltHOMEWORK:PrepareforReading.
