资源描述：
《高中人教版英语Book 3 Unit 4 根据课文改编的语法填空.doc》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、Book3Unit4HOWLIFEBEGANONTHEEARTH根据课文改编的语法填空Nooneknowsexactly______theearthbegan,asithappenedsolongago.However,accordingtoawidely______(accept)theory,theuniversebegan_____a"BigBang"thatthrewmatterinalldirections.Afterthat,atomsbegantoformandcombinetocreatestarsan
2、dotherbodies.Forseveralbillionyears______the"BigBang",theearthwasstilljustacloudofdust.______itwastobecomewasuncertainuntil_____4.5and3.8billionyearsagowhenthedustsettledintoasolidglobe.Theearthbecamesoviolent______itwasnotclear______theshapewouldlastornot.Itexp
3、lodedloudlywithfireandrock.Theywereintimetoproducecarbon,nitrogen,watervapourandothergases,______weretomaketheearth'satmosphere.______isevenmoreimportantisthat______theearthcooleddown,waterbegantoappearon_____surface.WaterhadalsoappearedonotherplanetslikeMars___
4、___but,unliketheearth,ithaddisappearedlater.Itwasnotimmediatelyobvious_____waterwastobefundamentaltothe_____（develop）oflife.Whatmany______(science)believeisthatthecontinuedpresenceofwaterallowedtheearthtodissolve_____（harm）gasesandacidsintotheoceansandseas.Thisp
5、roduced______chainreaction,whichmade_____possibleforlifetodevelop.Manymillionsofyearslater,thefirstextremelysmallplantsbegantoappearonthesurfaceofthewater.They_____（multiply）andfilledtheoceansandseaswithoxygen,_____encouragedthelaterdevelopmentofearlyshellfishan
6、dallsortsoffish.Next,greenplantsbegantogrowonland.They_____(follow)intimebylandanimals.Somewereinsects.Others,calledamphibians,wereabletoliveonlandaswellasinthewater.Laterwhentheplantsgrewintoforests,reptiles_____(appear)forthefirsttime.Theyproducedyounggenerall
7、yby_____(lay)eggs.Afterthat,somehugeanimals,calleddinosaurs,developed.They_____(lay)eggstooandexistedontheearthformorethan140millionyears.However,65millionyearsagotheageofthedinosaursended._____theysuddenlydisappearedstillremainsamystery.This_____(disappear)made
8、possibletheriseofmammalson_____earth.Theseanimalsweredifferent_____alllifeformsinthepast,becausetheygavebirthtoyoungbabyanimalsand_____(produce)milktofeedthem.Finally
