【完美导学】Unit 5 A delicate world Period 1 Starting out and understanding ideas 课件-2022-2023学年高中英语同步备课(外研版2019选择性必修第二册)

Unit5AdelicateworldPeriod1Startingout&UnderstandingideasWhatishappeninginthepictures?Startingout

extensivedeforestationleadto......1.serioussoilerosion;2.desertification;3.shorageoffreshwater;4.Severedrought......Lookatthesatelliteimages1.Whatishappeningtothearea?Thewaterareaisshrinking.2.Whatwouldalatersatelliteimageshow?Thewaterareawillbesmaller.3.Whatdoyouthinkcausedthesechanges?Maybeit'sduetooverexploitation;orhumanoverexploitation.Watchthevideo1.ArehumanspartofEarth'secosytems?Why?2.Inwhatwayscanhumansaffectecosytems?Reference:A.Manisapartofnature.Humanactivitieshavebecomeaninfluenceonthestabilityofthenaturalenvironmentofallspheresonearth.B.Degradationofforestandgrasslandvegetation,lossofbiodiversity,soilerosion,pollutionaggravating,thegreenhouseeffectoftheatmosphere,andthedestructionoftheozonelayer,havesoundedthealarmforhumanbeings.MacquarieIslandfromChoastoConservationUnderstandingideas1.Animalsinthepictures:___________________penguins,abird2.Whatkindofchangeswouldtakeplaceifcats,ratsandrabbitswereintroducedtoanenvironmentlikethis?Possibleanswers:a.Thepenguin'shabitatwillbedestroyedb.Ecosystemsacrosstheislandwillchangecomepletelyovertime.c.....WhathappenedtoMacquarieIsland?Ratsatethebirds'eggs.Catshuntedratsandmice.Catshuntedbirdsforfood.WhathappenedtoMacquarieIsland?KeeprabbitsformeatRabbitswererampant.andatethenativevegetationanddiggingholes.Parakeetsdiedoutin1891

Aviciouscycleofdestroyingnaturalbalance1.Invasivealienspeciesareoneofthebiggestcausesofbiodiversitylossandspeciesextinction.2.Alieninvasivespeciessuchasanimals,plantsorotherorganismsareintroducedtoanewnativeenvironment,whichmayadverselyaffectthebiodiversityecosystemservicefunctionorhumanwelfare.ThestructureandthethemeofthetextPartsParagrphsThemainideaPart1Para1Part2Para2,3,4,5Part3Para6Introducethepresentecologicalsituationoftheisland.Ecologicalchaoshappenedtotheislandinthepast.Aprogramhasbeenmadetoprotecttheisland.

Readingcomprehension

Choosetheauthor'spurposeinwritingthepassageandgiveyourreason.A.ToanalysehowMacquarieIslandwassavedfromdestruction.B.ToinformreadersofthechaoscausedonMacquarieIslandbyhumans.C.ToentertainreaderswithafunnyaboutwhathappenedonMacquarieIsland.D.Tosuggestwaysinwhichanecosystemcanbeprotected.Suggestedanswer:_____

A

LookfordetailsfromthetextActionsPurposesResultsHumansarrivedontheislandTolivethereRatsandmicewerebroughttherebyaccident,andTocontroltheratsandmiceatebirds'eggsandattackedbabybirds.CatswerebroughttotheislandCatsatethebirdstoo.ActionsPurposesResultsRabbitswereintroducedtotheisland.asasourceoffoodforhumansRabbitsmultipliesandcausedsoilerosion,andprovidedplentifulfoodforthecats.Aviruswasreleasedontotheisland.Toremovealltherabbitfromtheisland.Therabbitpopulationdecreased.Poisonwasdroppedfromhelicopters.Tosolvetherat,mouseandrabbitproblem.Theisland'secologyisontheroadtorecovery.Think&SharePostreading1.Whatisyourunderstandingof“...wehumnasoweittotheislandtogiveitahappyending”?Thedestructionoftheisland'secosystemwascausedbyanimalsthathumanshadaccidentallybroughtwiththem.Humaninterventionhasfurtherunderminedtheisland'secologicalbalance.Somanshouldmakeanattempttorestoretheisland'snaturalbalance.Think&Share2.Doyouthinkitwasrighttoeradicatethe“pest”fromMacquarieIsland?Giveyourreasons.1.Ithinkitwrongtoeradicatethe“pest”there.Herearesomereasons.2.Withoutpests,therewouldbenocreaturesthatfeedonthem,andcountlesscreatureswouldbewipedout,causinggreatdamagetobiodiversityandresultinginamoreseriousconsequencethantheexistenceoftheseso-calledpests.

Think&Share

3.Howcouldsimilarsituationsbeavoidedinthefuture?

1.Theintroductionofbiologicalspeciesresourcesfromabroadshallberegisteredorexaminedandapprovedaccordingtolaw,andcorrespondingsafetycontrolmeasuresshallbetaken.2.Thegovernmentshouldmakethecontinuousimprovementoftheexistinglawsontheintroductionofalienspecies.3.

Deepeninginternationalcooperation,preventionandcontrolofalienspeciesinvasionwillsurelyachievegreaterresults.Languageappreciation1.Thisinturnledtomorecatshuntingthebirds.Theendresultwasthatparakeets,oncelargeinnumberandnativetotheisland.•[句式分析]“inturn”:反过来；“morecatshuntingthebirds”动名词的复合结构作宾语；“thatparakeets....theisland”为that引导的表语从句。•[尝试翻译]这反过来又导致更多猫捕食鸟类。最终结果是，曾经数量众多，原产于该岛的长尾鹦鹉于1891年灭绝了。Languageappreciation2.Expertsfeltitnecesarytocomeupwithaplantoremovealltherabbitsfromtheisland.•[句式分析]“feltitnecessary”构成动词+it

(“it”作形式宾语)+adj(作宾语补足语)，“tocomeupwithaplan”不定式短语为真正主语后置；“toremovealltherabbitsfromtheisland”为不定式短语作后置定语，修饰plan.•[尝试翻译]专家认为有必要提出一项计划，把所有的兔子从岛上赶走。Languageappreciation3.Itturnedoutthattheydevelopedanimmunitytothevirus,andtheirnumbersexplodedonceagain.•[句式分析]“It