外研版（2019）选择性必修 第二册Unit 5 A delicate world Using language(2)课件

Usinglanguage(2)—ListeningandSpeaking1.Getthemainideaofthelisteningmaterial;2.Understandtherelationshipsbetweendifferentspeciesandtheimportanceofecologicalbalance.Lookatthediagramandanswerthequestions.51.Whatdoesthediagramshow?2.Whataretherelationshipsbetweenthelivingthings?

Thediagramshowsafoodchain—theconnectionbetweenthelivingthings.Thelivingthingsarecloselyconnectedwitheachotherbythefoodtheyeat.Secondaryconsumerspreyonprimaryconsumers,primaryconsumersfeedonproducers,andproducers

absorblightfromthesun,andwateranddissolvednutrientsfromthesoil,whichareprovidedbydecomposers.Inawoodlandecosystem,treesandotherplantsareproducers.They1._______water,andtakeinnutrientsfromthesoilandenergyfromthesun.Insectsareanexampleofaprimaryconsumer.They2.

_______theproducerstoprovidefoodforthem,andare3.

_______bysecondaryconsumers:smallmammalsandbirds.They4.

_______theprimaryconsumers.Worms,fungiandbacteriaaredecomposers.They5.

__________animalwasteandtheremainsoflivingthings.Thechemicalsthesedecomposers6.

________fertilisethesoilandgivetheplantsthenutrientstheyneedtogrow.absorbrelyonfedonpreyonbreakdownrelease6CompletethespeechwiththecorrectformofthewordsandexpressionsinActivity5.•Oneoftheoldestspeciesintheecosystem,thehoneybeehasbeeninexistenceformillionsofyears.•Ahoneybeecanflyasfastas24kilometresperhouranditswingscanbeat200timespersecond.•Injustonejourneytocollectpollenandnectar,onesinglehoneybeecanpollinateasmanyas50to100flowers.7Listentotheconversationandchoosethetruestatements.1Beesareveryimportanttoourfoodsupplybecausetheyprovidehoney.2Thebeepopulationisdeclining.3Withoutbees,humanswoulddieout.4Allhumancropsdependonbeesforpollination.5Ifbeesbecameextinct,otherinsectscouldpollinateenoughcrops.6Humansareresponsibleforthedeclineinthebeepopulation.√√√8Listenagainandcompletetheflowchart.Acombinationofthingsdamagesbeehabitats,mainly1.____________________________.pesticidesandclimatechangeThebeepopulationis2.______________________.Accordingtostatistics,beenumbersintheUS3.___________________injustoneyear.decliningveryquicklyhavefallenby17%Withoutbees,cropswould4.___________________.5._____________wouldnotbeabletocompensateforthelossofbees,because6.__________________________________________ofthespeciesofcrops.beunabletoreproduceOtherinsectsbeesareresponsibleforpollinatingabout70%Animalsthatliveonthecrops7._______________.Humanshavenothingtoeatanddieout.woulddieoutExpressingdoubtRespondingtodoubtYoumustbekidding!•

Areyousureabout...?

Idon’tbelieveit!•Checkitoutforyourself...It’safact! •Accordingtostatistics...Don’tforgetthat…•Youmustbekidding!•Idon’tbelieveit!•

Areyousureabout...?

•It’safact!•Don’tforgetthat…•Checkitoutforyourself...

•Accordingtostatistics...9Completetheboxeswiththeexpressionsfromtheconversation.Meg:HeyOllie,haveyouheardthatthebeepopulationisdeclining?Ollie:No,Ihaven’t.But,thinkingaboutit,Ihardlyeverseebeesthesedays.WhenIwaslittle,theyseemedtobeeverywhere!Meg:If

beesdieout,humanswilldieouttoo.Ollie:What?!Youmustbekidding!Idon’tbelieveit!Meg:It’safact!!Iwatchedanaturedocumentaryallaboutittheotherevening.Beesareveryimportanttoourfoodsupply.Ollie:Howcanthatbepossible?Humanswon’tdieoutjustbecausethere’snohoney!Meg:Beesdon’tjustmakehoney.Don’tforgetthatbeesarealsoresponsibleforpollinatingplants.Withoutthem,cropswouldbeunabletoreproduce.Ollie:Butsurelythereareotherwaysofgettingthesecropstoreproduce.Doesithavetobebees?Meg:Well,thereareotherinsectsthatpollinateplants,butit’sunlikelythattheywouldbeabletofullycompensateforthelossofbees.Beesareresponsibleforpollinatingabout70%ofthespeciesofcrops.ListeningmaterialsOllie:Areyousureaboutthatdata?Itsoundsratherexaggerated.Meg:Watchthedocumentaryandcheckitoutforyourselfifyoudon’tbelieveme.Withoutbees,numerousplantspecieswoulddieout.Animalsthatliveonthecropswoulddieout,andwewouldn’thaveenoughtoeat.Ollie:Seriously?That’sscary!Butlookingonthebrightside,therearemillionsandmillionsofbees.They’renotgoingtodieoutanytimesoon.Meg:I’mafraidyou’rewrong.Thebeepopulationisdecliningveryquickly.Accordingtostatistics,beenumbersintheUShavefallenby17%injustoneyear.Ollie:Gosh!Whatcausedthat?Meg:Acombinationofthings,really,butit’smainlyduetodamagetotheirhabitatscausedbypesticidesandclimatechange.Olli