人教版英语选修八unit5Using-Language.ppt

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1、选修8英语教学课件系列Unit5MeetingyourancestorsUsingLanguageTheworkonearlypeopledependsonthedatesgiventothebonesthatarefound.Ifthedatesarewrong,allthedataaboutearlypeoplemayalsobewrong.SoZhouHepingisveryinterestedtofindouthowarchaeologistsmakesurethattheirdatesareaccu

2、rate.ListeninganddiscussingyogurtpotsorangeskinwastepaperusedenvelopesThewastepaperbasket1ListentoPart1ofthetapeandtrytounderstand“thewastepaperbasket”diagramontherightandfillinthelayers.Itusesradioactivitytomeasuretheamountof_______inlivingthings.The______

3、_inadeadbody__________ata______rate.Weknowhowlongthattakes,sowecanmeasuretheamountof_______and_________howoldaboneis.carboncarbondisappearsfixedcarbonworkout2ListentoPart2andcompletethepassagebelow.3Lookatthisarchaeologicaldrawingofasectionshowingbuildingsa

4、tdifferenttimesandworkouttheorderinwhichtheywerebuilt.Writeyouranswerbelowandcheckwithyourpartner.Remembertogiveareasonforyouranswerinyourdiscussion.TheoldestbuildingisBbecauseithasnolayersunderneathit.ThesecondoldestbuildingisCbecauseithasnolayerunderneath

5、it.ThatlayeristheremainsofthebuildinginB.ThemostrecentbuildingisbuildingA.Ithastwolayersunderneath.TheyaretheremainsofbuildingsBandC.ZH:Howcanyoutellhowoldbonesarewhenyoufindthem?LISTENINGTEXT(P42)DATINGMETHODSZhouHepinghascometoaskthearchaeologist,RichardL

6、eakey,howhedatestheboneshefinds.Part1RL:Therearetwomainways:thefirstuseslayersinthegroundandthesecondusestheradiocarbondating.ZH:Howdoesthelayermethodwork?RL:Well,Lookatthediagraminyourbook.Thinkofyourwastepaperbasket.Whenyoucameintoworkyouthrewtheorangeski

7、nintoit.That’slayernumber1.Latersomebodythrewyogurtpotsintoit.That’slayernumber2.ZH:Ohyes,andthenIthrewsomepaperintoit.Sothat’slayernumber3.RL:Yes,andfinallysomeonethrewsomeusedenvelopes.Sohowmanylayersarethereinthiswastepaperbasket?ZH:TherearefourRL:Good.N

8、owwhichlayeristhefirstandthereforetheoldest?ZH:Theorangeskin.RL:Andwhichisthelastandthereforethemostrecent?ZH:Ofcourse-theusedenvelopes.Iseehowitworksnow.Buthowdoesithelp?RL:Well,layersofsoilareproduce