Unit+5+A+delicate+World+Listening+and+speaking 高二英语外研版（2019）选择性必修第二册

Unit5Period3ListeningandSpeaking新课导入What'syourunderstandingofthefoodchain?课堂学习1Lookatthediagramandanswerthequestions.Payattentiontothewordsandexpressionsinbold.1Whatdoesthediagramshow?2Whataretherelationshipsbetweenthelivingthings?1Whatdoesthediagramshow?Thediagramshowsafoodchain-theconnectionbetweenthelivingthings.2Whataretherelationshipsbetweenthelivingthings?Thelivingthingsarecloselyconnectedwitheachotherbythefoodtheyeat.Secondaryconsumerspreyonprimaryconsumers,primaryconsumersfeedonproducers,andproducersabsorblightfromthesun,andwateranddissolvednutrientsfromthesoil,whichareprovidedbydecomposers.2Completethepassagewiththecorrectformofthewordsandexpressions.absorb,dissolvednutrients,relyon,provideenergy,feedon,preyon,breakdown,releasedInawoodlandecosystem,treesandotherplantsareproducers.They

1____________waterandtakeinnutrientsfromthesoilandenergyfromthesun.

Insectsareanexampleofaprimaryconsumer.They2____________theproducerstoprovidefoodforthem,andare3____________bysecondaryconsumers:smallmammalsandbirds.They4____________theprimaryconsumers.Worms,fungiandbacteriaaredecomposers.They5____________animalwasteandtheremainsoflivingthings.Thechemicalsthesedecomposers6____________fertilisethesoilandgivetheplantsthenutrientstheyneedtogrow.absorbrelyonfedonpreyonbreakdownrelease•Oneoftheoldestspeciesintheecosystem,thehoneybeehasbeeninexistenceformillionsofyears.•Ahoneybeecanflyasfastas24kilometresperhouranditswingscanbeat200timespersecond.•Injustonejourneytocollectpollenandnectar,onesinglehoneybeecanpollinateasmanyas50to100flowers.DidYouKnow?3Listentotheconversationandchoosethetruestatements.1.Beesareveryimportanttoourfoodsupplybecausetheyprovidehoney.2.Thebeepopulationisdeclining.3.Withoutbees,humanswoulddieout.4.Allhumancropsdependonbeesforpollination.5.Ifbeesbecameextinct,otherinsectscouldpollinateenoughcrops.6.Humansareresponsibleforthedeclineinthebeepopulation.4Listenagainandcompletetheflowchart.Acombinationofthingsdamagesbeehabitats,mainly1_____________.Thebeepopulationis2_____________.Accordingtostatistics,beenumbersintheUS3_____________injustoneyear.Withoutbees,cropswould4_____________.5_____________wouldnotbeabletocompensateforthelossofbees,because6_____________ofthespeciesofcrops.Animalsthatliveonthecrops7_____________.Humanshavenothingtoeatanddieout.↓Answers:

1.pesticidesandclimatechange2.decliningveryquickly3.havefallenby17%4.beunabletoreproduce5.Otherinsects6.beesareresponsibleforpollinatingabout70%7.woulddieout5Completetheboxeswiththeexpressionsfromtheconversation.•Youmustbekidding!•Idon'tbelieveit!•It'safact!•Don'tforgetthat...•Areyousureabout...?•Checkitoutforyourself...

•Accordingtostatistics...RespondingtodoubtExpressingdoubt•Youmustbekidding!•Idon'tbelieveit!•Areyousureabout...?•It'safact!•Don'tforgetthat...•Checkitoutforyourself...•Accordingtostatistics...6Workinpairs.Talkaboutwhatwouldhappentotheecosystemifanotherspeciesdiedout.Usethewordsandexpressionsinthissection.Nowthinkabouthowyourknowledgehelpedyoucontributetothediscussion.Example:Developing:Icanusesomeusefulwordsandexpressions,andgivesomeroughideasduringthediscussion.Satisfactory:Icanusecorrectwords,expressionsandcompletesentencestoclearlyshowmyideasduringthediscussion.Exemplary:Icanuseaclearstructurewithproperwordsand