选择性必修一Unit3Lesson1课件高中英语课件（北师大版2019必修一）

——Unit3Conservation——Lesson1TheSixthExtinction高二精耕团队

范冬烨Basedonthevideo/yourknowledge.Howmuchdoyouknowaboutextinction?-E11.HowmanytimesuptotodayhaslifeonEarthalmostdiedout?A.Once.B.Fivetimes.C.Morethan10times.2.AboutwhatpercentofallspeciesonEarthbecameextinctduringthemassextinctionknownasthe"GreatDying"?A.Lessthan10%.B.Nearly50%.C.Morethan90%.3.Whatdoscientiststhinkwillcausethenextmassextinction?A.Humanactivity.B.Naturalcauses.C.Unknownreasons.√√√solutionseffectscauses/reasonsbackgroundhistoryReadforStructurePara1Para2Para3Para4TheSixthExtinctionReadandExplore-E3Completethenotesandtalkaboutthedifferentaspectsofextinctions.Checkyouranswer1.Meaningofextinction:2.Thenumberofextinctionsoccurredsofar:entirespeciesarewipedoutover90%ofallspeciesthateverlivedCheckyouranswer3.Twonotableextinctionsandtheirconsequences:4.Mainreasonsthatcauseextinctions:thethirdmassextinction,killed90%to96%ofallspecies;thefifthevent,whichoccurred66millionyearsago,causedthedeathofthedinosaursvolcaniceruptions,asteroidshittingtheEarthfromspace,changesinsealevels,thedecreaseofoxygencontentofthesea,globalwarmingCheckyouranswer5.Howtoavoidthesixthmassextinction:

changethewaywelive,includingsettingupspecialareaswhereplantsandanimalscanbeprotected;changehowweworkandtravelbyusingcleaner,morenaturalsourcesofenergy;improveourfarmingmethodsReadandanswer1.Whatdidscientistsfindoutin2015?2.Whydoesthewriterthinkthesixthmassextinctionwillcome?3.Whydoesthewriterbelievewe'llprobablydieoutif75%oftheEarth'sspeciesdieout?4.Whatdidpeopledointhecasestudytoprotectblackrobins?Whichclaim(s)didthecasestudysupportinthetext?Readandanswer1.Whatdidscientistsfindoutin2015?2.Whydoesthewriterthinkthesixthmassextinctionwillcome?Readandanswer3.Whydoesthewriterbelievewe'llprobablydieoutif75%oftheEarth'sspeciesdieout?4.Whatdidpeopledointhecasestudytoprotectblackrobins?Whichclaim(s)didthecasestudysupportinthetext?It’snevertoolatetohelpSummarydieoutbeknownashaveaffecteddependonwipeouttakestepstakeactionssetuptakecareofInthelast500millionyears,therehavebeenfivemassextinctioneventsonEarth.Inthethirdevent,which1the"GreatDying",90%to96%ofallspecies2.Ofcourse,speciesdiedoutduetomanycauses.Butnowadays,humanactivity3alltypesofspeciesthatwe4forliving.Weneedto5

toavoidthesixthmassextinction.isknownasdiedout

hasaffecteddependon

takeactionSummarydieoutbeknownashaveaffecteddependonwipeouttakestepstakeactionssetuptakecareof

Weshould6tosaveendangeredanimalsandplants,and7specialareasto8thembeforethenextextinctioncomesthatmay9theentirespecies.takestepssetuptakeca