高中英语必修三第四单元课件.ppt

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1、Unit4Astronomy:thescienceofthestarsHowmuchdoyouknowabouttheuniverse?Whatarethenamesoftheeightplanetsthatcircleoursun?Whatistheirorderfromthesun?地球______木星______火星______水星________海王星_______土星________天王星_______金星________EarthJupiterMarsMercuryNeptuneSaturnUranusVenusTHESOLARSYST

2、EM1.Howoldistheuniverse?2.Howoldistheearth?3.Whichwerethefirstcreatureorplantsonearth?4.Doyouknowwhattheorderforthedevelopmentofplantsandanimalsis?Severalbillionyearsago.Between4.5and3.8billionyearsago.Verysmallair-breathingcreatures.FreeTalkIdeasabouthowlifebeganreadingHowLif

3、eBeganontheEarthFastreadingReadthepassagequicklyandfindthemainidea.Abriefintroductiononhowtheuniversedevelopedandhowlifebeganontheearth.CarefulreadingPara1:Para2:Para3:Para4:Para5:Awidelyacceptedtheoryabouttheformationoftheuniverse.Theformationoftheearth.Theimportanceofwaterfo

4、rlife.Thedevelopmentofplantsandanimalsontheearth.Thearrivalofhumansandtheirimpactontheearth.Readthepassagecarefullyandanalyseitsstructure.earth,atmosphereandwaterlifedevelopmenthumanbeings1.Whatistheoriginalearth’satmospheremadeupof?2.Whydidscientistsbelievewaterisfundamentalt

5、othedevelopmentoflife?3.Howdidwatercomeintobeingontheearth?4.Whichkindoflife-beingfirstappearedontheearth,plantsoranimals?Why?5.Whyweremammalsdifferentfromalllifeformsinthepast?Answerthefollowingquestions.Carbon,nitrogen,watervapour,andothergases.2.Whydidscientistbelievewateri

6、sfundamentaltothedevelopmentoflife?Becausewaterallowedtheearthtodissolveharmfulgasesandacidsintotheoceansandseastoensureafollowingchainreaction,whichmadeitpossibleforlifetodevelop.Whatistheoriginalearth’satmospheremadeupof?3.Howdidwatercomeintobeingontheearth?Theexplosionofthe

7、earthproducedwatervapor,whichturnedintowaterwhentheearthcooleddown.4.Whichkindoflife-beingfirstappearedontheearth,plantsoranimals?Why?Atfirst,smallplantsbegantoappearonthesurfaceofthewater,theyproduceoxygen,whichencouragedthelaterdevelopmentofearlyshellfishandallsortsoffish.5.

8、Whyweremammalsdifferentfromalllifeformsinthepast?Theywerediff