Unit 3 Lesson 1 The Sixth Extinction课件 -2022-2023学年高中英语北师大版2019选择性必修第一册

Unit3ConservationLesson1TheSixthExtinction重点单词1．____________n.物种，种2．____________adj.异常的；不平常的3．____________adj.大量的4．____________adj.各种各样的，形形色色的5．____________vi.&vt.减少

n.减少；减少的量6．____________vt.责怪，指责7．____________vt.影响8．____________adj.濒危的9．____________adj.太阳光（能）的10．____________vi.&vt.（使）孵化11．____________vt.（使）恢复species

unusual

mass

varied

decreaseblame

affect

endangered

solar

hatch

restore

重点词块1．attherateof…________________2．bebasedon…________________3．layeggs________________4．beatrisk________________5．wipeout________________6．dieout________________7．upto…________________8．inshort________________9．accordingto________________10．takesteps________________11．betoblame________________

以……的速度/比例基于……

产卵/下蛋处境危险；受到威胁彻底毁灭消失；绝迹；灭绝高达……

简而言之根据；按照采取措施把……归咎于

练一练extinctionspecieswipesthoutglobalwarmingdieoutasituationinwhichsomethingnolongerexistsindangerofbeingharmedorlostthenaturalenvironmentinwhichananimalorplantusuallylivesasetofanimalsorplantsinwhichmembershavesimilarcharacteristicstoeachothertodestroysomethingcompletelyagradualincreaseinworldtemperaturescausedbygasessuchascarbondioxidethatarecollectingintheairaroundtheEarthandstoppingheatescapingintospacetobecomelesscommonandfinallystopexistingendangeredhabitat(

)1.HowmanytimesuptotodayhaslifeonEarthalmostdiedout?a.Once.b.Fivetimes.c.Morethan10times.Activity1Howmuchdoyouknowaboutextinction?Choosetheoptionbasedonyourknowledge.(

)2.AboutwhatpercentofallspeciesonEarthbecameextinctduringthemassextinctionknownasthe“GreatDying”?a.Lessthan10%.b.Nearly50%.c.Morethan90%.(

)3.Whatdoscientiststhinkwillcausethenextmassextinction?a.Humanactivity.b.Naturalcauses.c.Unknownreasons.bcaActivity2Extinctions,whereentirespeciesarewipedout,arenotunusualinourEarth’shistory.Infact,over90percentofallspeciesthateverlivedarenowextinct.Inthelast500millionyears,therehavebeenfivetimeswhenlifeonEarthhasalmostended.Theseincludethethirdmassextinction,knownasthe“GreatDying”,whichkilled90%to96%ofallspecies.Andthefifthevent,whichoccurred66millionyearsago,causedthedeathofthedinosaurs.Thereasonsforextinctionsarevaried.Accordingtoscientists,theyincludevolcaniceruptions,asteroidshittingtheEarthfromspace,changesinsealevels,thedecreaseoftheoxygencontentoftheseaandglobalwarming.ManyscientistssaywearenowenteringtheEarth’ssixthmassextinction.Thistime,humanactivitywillbetoblamReadatextaboutextinction.ThencheckyouranswersinActivity1.Activity2Althoughitisnotunusualforspeciestodieoutnaturally,therateatwhichthisisnowhappeningiscauseforconcern.A2015studybyscientistswhowerebasedatBrownUniversityandDukeUniversityintheUS,lookedathowquicklyspeciesdieoutduetonaturalcauses,thatis,the“backgroundextinctionrate”.Theyfoundthathumanactivityiscausingspeciestodieout1,000timesfasterthannormal.Thereisalonglistofreasonswhysomanyspeciesaredyingout:airandwaterpollution,forestsbeingdestroyed,factoryfarmingandoverfishing.ItisclearthathumanactivityhasnegativelyaffectedallotherspeciesonEarth,includinganimalsandplants.Readatextaboutextinction.ThencheckyouranswersinActivity1.Activity2Ifasixthmassextinctionoccurs,scientistswhohavestudiedtheissuebelievethatuptothreequartersofallspeciesonEarthcoulddieout.Ofcourse,aswehumansdependonsomanyspeciesforoursurvival,wewouldalsobeatriskofdyingout.Ourworldandourlivesdependonthebalanceinnaturebetweenanimalsandplants.Withoutforests,wewouldhavenoairtobreathe,andwithoutcleanwaterwewouldbeunabletosurvive.Readatextaboutextinction.ThencheckyouranswersinActivity1.Activity2Canasixthextinctionbeavoided?Expertssaythatitisnotyettoolate,ifwetakeactionnow.Thiswouldmeanwehavetosignificantlychangethewaywelive.Forexample,weneedtotakestepstosaveendangeredspecies,includingsettingupspecialareaswhereplantsandanimalscanbeprotected.Weneedtochangehowweworkandtravelbyusingcleaner,morenaturalsourcesofenergy,suchaswindandsolarenergy.Wealsoneedtoimproveourfarmingmethodstoreducewater,airandlandpollution.Inshort,ifwewanttosurvive,weneedtostopdestroyingtheplanetthatweliveonandstarttoprotectit.Readatextaboutextinction.ThencheckyouranswersinActivity1.TheBlackRobinBlackrobinsarethebirdsthathumanssavedfromextinction.In1980,therewereonlyfiveblackrobinsleftintheworld.TheyalllivedonasmallislandoffthecoastofNewZealand.Onlyoneofthosebirds,afemalecalledOldBlue,wasabletolayeggs.Wildlifeworkersbeganaprogrammeforraisingblackrobinchicks.TheyprotectedOldBlue’seggs,helpedthemtohatch,andtookcareofthechicks.Thankstotheirefforts,therearenowmorethan250blackrobins,andthepopulationisspreading.Tohelpthemsurvive,peoplearerestoringtheirhabitatsandremovingsmallanimalsthathuntthem,suchasmiceandcatsfromtheislandswheretheylive.CaseStudyNotesrobinn.知更鸟habitatn.栖息地Activity3MeaningofextinctionHowtoavoidthesixthmassextinctionMainreasonsthatcauseextinctionsTwonotableextinctionsandtheirconsequencesThenumberofextinctionsthathaveoccurredsofarExtinctionReadthetext.Completethenotes.Thentalkaboutthedifferentaspectsofextinctions.1.

Meaningofextinction:entirespeciesarewipedoutover90%ofallspeciesthateverlivedthethirdmassextinction,whichkilled90%to96%ofallspecies;thefifthevent,whichoccurred66millionyearsago,causedthedeathofthedinosaursvolcaniceruptions,asteroidshittingtheEarthfromspace,changesinsealevels,thedecreaseofoxygencontentofthesea,globalwarming3.Twonotableextinctionsandtheirconsequences:4.Mainreasonsthatcauseextinctions:2.Thenumberofextinctionsthathaveoccurredsofar:Activity3changethewaywelive,e.g.saveendangeredspecies,includingsettingupspecialareaswhereplantsandanimalscanbeprotected;changehowweworkandtravelbyusingcleaner,morenaturalsourcesofenergy;improveourfarmingmethods5.Howtoavoidthesixthmassextinction:Readthetext.Completethenotes.Thentalkaboutthedifferentaspectsofextinctions.1.

Whatdidscientistsfindoutin2015?Thestudyfoundhowquicklyspeciesdieoutduetonaturalcauses,thatisthe“backgroundextinctionrate”.Theyfoundthathumanactivityiscausingspeciestodieout1,000timesfasterthannormal.BecausehumanactivityhasnegativelyaffectedallotherspeciesonEarth,includinganimalsandplants.2.Whydoesthewriterthinkthesixthmassextinctionwillcome?Activity4Readagain.Answerthequestions.Becauseourworldandourlivesdependonthebalanceinnaturebetweenanimalsandplants.3.Whydoesthewriterbelievewe’llprobablydieoutif75%oftheEarth’sspeciesdieout?Activity4PeopleprotectedOldBlue’seggs,helpedthemtohatch,andtookcareofthechicks.Peoplearerestoringtheirhabitatsandremovingpestslikemiceandcatsfromtheislandswheretheylive.Thecasestudyshowedthatevenindesperatesituations,wecandosomethingtohelp.Inshort,it’snevertoolate.4.Whatdidpeopledointhecasestudytoprotectblackrobins?Whichclaim(s)didthecasestudysupportinthetext?Readagain.Answerthequestions.Inthelast500millionyears,therehavebeenfivemassextinctioneventsonEarth.Inthethirdevent,which1.__________the“GreatDying”,90%to96%ofallspecies2._________.Ofcourse,speciesdiedoutduetomanycauses.Butnowadays,humanactivity3.___________alltypesofspeciesthatwe4.___________forliving.Weneedto5.___________toavoidthesixthmassextinction.Weshould6.__________tosaveendangeredanimalsandplants,and7._______specialareasto8.___________thembeforethenextextinctioncomesthatmay9._________theentirespecies.Activity7

dieoutbeknownashaveaffecteddependonwipeouttakestepstakeactionsetuptakecareof

Completetheparagraphaboutextinctionsusingthecorrectformofthephrasesbelow.isknownasdiedouthasaffecteddependontakeactiontakestepssetuptakecareofwipeoutActivity8Readthesentencesanddiscusswhichword(s)theclauses(initalics)referto.1.Extinctions,whereentirespeciesarewipedout,arenotunusualinourEarth’shistory.“whereentirespeciesarewipedout”

refersto“Extinctions”2.Theseincludethethirdmassextinction,knownasthe“GreatDying”,whichkilled90%to96%ofallspecies.“whichkilled90%to96%ofallspecies”

referstothe“GreatDying”3.A2015studybyscientistswhowerebasedatBrownUniversityandDukeUniversityintheUS,lookedathowquicklyspeciesdieoutduetonaturalcauses...“whowerebasedatBrownUniversityandDukeUniversityintheUS”

refersto“scientists”Activity8Readthesentencesanddiscusswhichword(s)theclauses(initalics)referto.4.Ifasixthmassextinctionoccurs,scientistswhohavestudiedtheissuebelievethatuptothreequartersofallspeciesonEarthcoulddieout.“whohavestudiedtheissue”

refersto“scientists”5.Weneedtotakestepstosaveendangeredspecies,includingsettingupspecialareaswhereplantsandanimalscanbeprotected.“whereplantsandanimalscanbeprotected”

refersto“specialareas”Whichoftheclausesabove:(1)giveinformationtoidentifythepersons/objects.(_____________)(2)giveextrainformationaboutapersonorathing,whichcanbeleftout.(________________)Focusonlanguage:Relativeclauses—DefiningclauseandNon-definingclausedefiningclausenon-definingclause用法（1）：彻底消灭，全部摧毁（具体的物品）

例句1.Thediseasethreatenstowipeouttheentirepopulation.

这种疾病有可能毁灭整个种群。

仿写：Avolcaniceruptionnearly_______________________ofMontserratin1997．

1997年的一次火山喷发差点把蒙特塞拉特这个小岛给毁灭了。用法（2）：去除，抹去（抽象的东西）

例句2.Ireallyhopesurgerycouldwipeoutthetiredfeelings.

我真的希望手术可以去除这些疲劳的感觉。

仿写：Adiseasehas________________________.

一场疾病把他所有的记忆都抹去了。词汇精讲(P52)

Extinctions,whereentirespeciesarewipedout,arenotunusualinourEarth’shistory.物种灭绝，即整个物种的完全消失，在地球历史上并不罕见。1．wipeout彻底毁灭wipedoutthesmallislandwipedoutallhismemories用法（1）：Itisunusual(forsb.)todosth.

做某事对某人来说是不寻常的

例句1.It’sunusualforhimtofeelveryangryinasituationlikethis.在像这样的情况下，他大发雷霆是不寻常的。词汇精讲(P52)Extinctions,whereentirespeciesarewipedout,arenotunusualinourEarth’shistory.物种灭绝，即整个物种的完全消失，在地球历史上并不罕见。2．unusual

adj.

异常的；不平常的用法（2）：Itisunusualthatsb.

dosth.

某人做某事是不寻常的

例句2.Itisnotunusualthatshereachesoutherhelpinghand.她经常出手相助。【词汇拓展】unusuallyadv.不寻常地usualadj.通常的usuallyadv.通常地thanusual比平时asusual像平常那样

词汇精讲2．unusual

adj.

异常的；不平常的【针对练习】

单句语法填空(1)Chopsticksare_________(usual)twolong,thinpiecesofwoodorbamboo.Theycanalsobemadeofplastic,animalboneormetal.(2)

Thistime,westayedtogether,incaseanythingelse_________

(usual)happened.(3)

Butafewdaysago,thisancienttownwas__________

(usual)fullofpeople.(4)Hewasan_________

(usual)manwithgreatbusinesstalents.usuallyunusualunusuallyunusual词汇精讲(P52)

Thereasonsforextinctionsarevaried.

物种灭绝的原因多种多样。3．varied

adj.

各种各样的，形形色色的【词汇拓展】

vary

vi.（根据情况）变化，改变；（大小、形状等）相异，不同

varywith…

随……而变化

varyfrom…

不同于……

varyin…

在……方面不同/有差异

varyfrom…to…

从……到……不等/不同【语言提升】variedadj.不同的，多变的，各种各样的，形形色色的（＝various）词汇精讲【针对练习】

单句语法填空

(1)

Thethreegroupsofviolinists________

(vary)alotintheirpracticetimeslastmonth.

(2)

In2020,WorldWildlifeDaycelebratedbiodiversity,includingwildfaunaandflora,inallits________

(vary)andbeautifulforms.

(3)

Ilikereadingbooksverymuch,especiallystorybooks,varyingfromChinesestories________Englishstories.

(4)

Changesinpricenormallyvary________changesofsupplyandneed.

(5)

ThoughLucyandLilyaretwins,theyvary________character.varied3．varied

adj.

各种各样的，形形色色的variedtowithin(P52)Althoughitisnotunusualforspeciestodieoutnaturally,therateatwhichthisisnowhappeningiscauseforconcern.虽然物种的自然灭绝并不罕见，但现在灭绝的速度令人担忧。4．dieout消失；绝迹，灭绝【词汇拓展】dieoff相继死去，先后死去diedown逐渐变弱，逐渐平息diefrom/of死于……dieaway逐渐减弱，逐渐消失bedyingforsth./todosth.渴望某物/做某事词汇精讲词汇精讲【针对练习】

单句语法填空

(1)

Thepreyspeciestheydirectlyattackwilldie________.

(2)

In2016,justover400,000peopledied________thedisease.

(3)Iamdying________aglassofwater.

(4)Thewindwilldie________intheevening.

(5)

Sofarworldwide,itisreportedthatmorethan90,000peoplehavebeeninfectedwiththenewcoronavirusandmorethan3,000havedied________lessthanthreemonths.outfromindown4．dieout消失；绝迹，灭绝for重点句式1.(P52)Inthelast500millionyears,__________________fivetimeswhenlifeonEarthhasalmostended.

在过去的5亿年里，曾经有5次地球上的生命几乎灭绝了。2.(P53)

________________humanactivityhasnegativelyaffectedallotherspeciesonEarth,includinganimalsandplants.

很明显，人类活动对地球上所有其他物种，包括动物和植物都产生了负面影响。3.(P53)

Withoutforest,we____________noairtobreathe.

没有森林，我们就没有呼吸的空气。therehavebeenwouldhaveItisclearthat句式精讲1.(P52)Inthelast500millionyears,therehavebeenfivetimeswhenlifeonEarthhasalmostended.

在过去的5亿年里，曾经有5次地球上的生命几乎灭绝了。▷therebe句型的用法：（1）本句是therebe句型的现在完成时。therebe结构中的be动词可以根据具体情况，有

一般现在时、一般过去时、一般将来时、begoingto结构、usedto结构等。

例句1.Thereusedtobeatowerbytheriver.

河边曾经有一座塔。

例句2.Therewillbeheavysnownextweekaccordingtoweatherreport.

根据天气预报，下周将有大雪。1．therebe句型的用法句式精讲（2）therebe结构还可以根据具体的情况，与同情态动词或seem，happen，remain等连用。

例句3.Theremustbesomeonetomeetyouwhenyouarrive.

你到了后，一定会有人接你的。

例句4.Thereseemstobesomeonecryinginthenextroom.

似乎隔壁有人在哭。（3）therebe句型中，be动词有时可用lie，stand，live，exist等替换，表示某个时候或某地有某物。

例句5.OnthesouthwestfrontierofChina,thereliemanyforestswhereliveagreatvarietyofplantsandanimals.

在中国西南边陲有许多森林，那里生长着各种各样的植物和动物。

例句6.Thereexistsanargumentaboutthearrangementfortheholidays.

关于度假的安排之事还存在争论。1．therebe句型的用法句式精讲(P53)

ItisclearthathumanactivityhasnegativelyaffectedallotherspeciesonEarth,includinganimalsandplants.

很明显，人类活动对地球上所有其他物种，包括动物和植物都产生了负面影响。【句式剖析】

本句中的It是一个形式主语。其后接的isclear是一个系表结构。后面的that从句在句中作真正的主语。（1）

在这个结构中，that从句的谓语部分通常是“should＋动词原形”。

例句1.Itisnecessarythatyoushouldbehavewellatschool.

在学校你应该表现好一点。2．itis＋形容词（表语）＋that从句（真正的主语）▷itis＋形容词（表语）＋that从句（真正的主语）句式用法：句式精讲2．itis＋形容词（表语）＋that从句（真正的主语）（2）这句型中的表语，除了是形容词外，还可以是名词。

例句2.Itisyourdutythatyoushouldtakegoodcareofyourparents.

照顾好你的父母是你的职责。（3）这个句型中的that从句可以转换成动词不定式短语forsb.todosth.。

例句3.Itisimpossiblethattheyshouldhavefinishedsomuchworkinsuchashorttime.

＝Itisimpossibleforthemtohavefinishedsomuchworkinsuchashorttime.

他们在这么短的时间内完成这么多的工作是不可能的。句式精讲(P53)

Withoutforest,wewouldhave

noairtobreathe.

没有森林，我们就没有呼吸的空气。【句式剖析】

本句的介词without引出的条件是一个假设的条件，句子的谓语动词这时用虚拟语气。（1）与现在事实相反；

谓语部分：would/could/might(not)dosth.

例句1.Withoutair,mancouldn’texistontheearth.

没有空气的话，人类将不能在地球上生存。3．without引导的虚拟语气▷without引导虚拟条件时，谓语动词要使用虚拟语气。这时，谓语动词有如下三种形式：句式精讲（2）与过去事实相反；

谓语部分：would/could/might(not)havedonesth.

例句2.Withoutyourhelp,Iwouldhavefailedtheexamlastweek.

没