课件英语选择性必修二Unit5Usinglanguage

Unit5AdelicateworldUsinglanguageITasanemptyobjectBYMICHELLEItasanemptyobjectPart01Lookatthesentencesandanswerthequestions.Sentences(a)and(c)arefromthereadingpassage.a

NovisitorwouldthinkitsurprisingthattheislandisaUNESCOWorldHeritageSite.b

NovisitorwouldthinkthattheislandbeingaUNESCOWorldHeritageSiteissurprising.c

Expertsfeltitnecessarytocomeupwithaplantoremovealltherabbitsfromtheisland.d

Expertsfelttocomeupwithaplantoremovealltherabbitsfromtheislandwasnecessary.1

Whatdoes“it”refertoinsentences(a)and

(c)?2Whatisthedifferencebetweenthesentencesineachgroup?Whentheobjectofasentenceisathat-clause(b)

oraninfinitive(d),wesometimesuse“it”asanemptyobjectandputtherealobjectlatertokeepbalance.Forexample,sentence(a)

uses“it”astheemptyobjectof“think”,referringtotherealobject:“theislandisaUNESCOWorldHeritageSite”.Sentence(b)usesthat-clauseastheobjectof“think”.Nowlookformoresentenceswiththisstructureinthereadingpassage,andsummariseitsuseinyourownwords.Thisincidentmadeitclearthattherat,mouseandrabbitproblemneededsolvingonceandforall.…butwehumansoweit

totheislandtogiveitahappyending.It作形式宾语条件真正的宾语是有宾语补足语不定式动名词从句具备了这两个条件，形式宾语it一定要用。it作形式宾语的常见情况归纳如下：1.it代替不定式短语。常用于：think/find/feel/consider/make/regard...it+adj./n.+todoIfinditpleasanttoworkwithhim.Theyfeltitdifficulttofinishtheworkinsuchashorttime.Shethinksitherdutytohelphim.Allthesenoisesmadeitimpossibleformetogoonwiththework.2.it代替v.-ing只限于少数句型。

consider/think/find...it+good/use/worthwhile...+doing...Theprofessorconsidersitnogoodreadingwithoutunderstanding.Doyouconsideritanyusearguingwithhim?Idon’tthinkitworthwhilegoingtosuchaplace.it作形式宾语的常见情况归纳如下：3.it代替宾语从句(that有时候可以省略)。think/find/make...it+n./adj.+ObjectClause...Weallthoughtitapitythattheconferencewascancelled.Theykeptitquietthathewasdead.Hehasn’tmakeitclearwhenheiscomingback.it作形式宾语的常见情况归纳如下：it作形式宾语还有几种特殊情况，归纳如下：动词+it+that从句，常见于put,have,take等动词后。Itakeitthathewillfinishthetaskbyhimself.动词+it+when/if从句，常见于appreciate,enjoy,like,prefer等动词之后。Wereallyappreciateitifyoucoulddousafavour.Weoweittoyouthatwearestillalive.Itookitforgrantedthattheywerenotcoming.动词+it+介词短语+that从句，常见于oweittosb,takeitforgranted等结构中。动词+介词+it+that从句，常见于lookto,dependon,insiston,stickto,answerfor等结构中。Sheinsistedonitthatshewasinnocent.Youmaydependonitthathewillhelpyou.Hemadeitknowntoeveryonethathewasright.Theyhaven’tmadeitknownwheretheyaretoholdtheconference.动词+it+过去分词+从句。根据括号内的汉语提示并用it作形式宾语补全下面句子。1._______________________(我认为那很重要)tofindapart-timejob.2._______________________________(新技术使之成为可能)toachieveabalancebetweeneconomicdevelopmentandecosystems.3._______________________(他们觉得很困难)torecovertheoriginalecosysteminsuchashorttimelastyear.4.______________________________________(你为何不让人们引起注意)thatouractions,nomatterhowsmalltheymaybe,makeadifferencetonature?IconsideritimportantNewtechnologiesmakeitpossibleTheyfeltitverydifficult

Whydon'tyoubringittopeople'sattentionRewritetheunderlinedpartsusingitasanemptyobject.manypeoplethinkitagoodideatokeepthisturtleasapetbelieveitnobigissuetoreleasethemintothewildpeoplehavefounditathreattootherspeciestoreleasetheseturtlesintothewildExpertsconsideritimportantforownerstokeeptheirpetsinanenclosedareaLookatpicturesofSaihanbaNationalForestParkandfindoutthechanges./LocatedinChengdeCity,HebeiProvince,Saihanba(塞罕坝)sits450kilometerstothenorthofBeijing.Theplaceiscoveredwithsnowsevenmonthsayear.Itusedtobeafreezing,barrendesertplaguedbysandstorms.However,ithasbeenturnedintotheworld’slargesthuman-madeforestthatcoversanareaofnearly75,000hectares.Thus,itiscalleda“greenmiracle.”BackgroundInformationnouns/adjectivestodo/thatbreakthroughimpossiblelikelyunrealistic...growinvestigateplanttreestransform...Nowdescribeitschangesusingitasanemptyobjectwhereappropriate.Youmayrefertothewordsandexpressionsinthetableforhelp.Ithinkitabreakthroughtotransformadesertintoaforest...Ithinkitimpossibletogrowtreesthereinthe1960s.IthinkitunrealistictoplanttreesinthedesertwhentheworkersfirstcametoSaihanba.EcosystemsPart02Lookatthediagramandanswerthequestions.Payattentiontothewordsandexpressionsinbold.Whatdoesthediagramshow?Whataretherelationshipsbetweenthelivingthings?

Whatdoesthediagramshow?Whataretherelationshipsbetweenthelivingthings?

Thediagramshowsafoodchain—theconnectionbetweenthelivingthings.Thelivingthingsarecloselyconnectedwitheachotherbythefoodtheyeat.Secondaryconsumerspreyonprimaryconsumers,primaryconsumersfeedonproducers,andproducersabsorblightfromthesun,andwateranddissolvednutrientsfromthesoil,whichareprovidedbydecomposers.CompletethepassagewiththecorrectformofthewordsandexpressionsinActivity5.Inawoodlandecosystem,treesandotherplantsareproducers.They1__________water,andtakeinnutrientsfromthesoilandenergyfromthesun.Insectsareanexampleofaprimaryconsumer.They2__________theproducerstoprovidefoodforthem,andare3__________bysecondaryconsumers:smallmammalsandbirds.They4__________theprimaryconsumers.Worms,fungiandbacteriaaredecomposers.They5_____________animalwasteandtheremainsoflivingthings.Thechemicalsthesedecomposers6__________fertilisethesoilandgivetheplantsthenutrientstheyneedtogrow.absorb

absorb

dissolvenutrients

relyon

provideenergy

feedon

preyon

breakdown

releaserelyonfedonpreyonbreakdownreleaseOneoftheoldestspeciesintheecosystem,thehoneybeehasbeeninexistenceformillionsofyears.Ahoneybeecanflyasfastas24kilometresperhouranditswingscanbeat200timespersecond.Injustonejourneytocollectpollenandnectar,onesinglehoneybeecanpollinateasmanyas50to100flowers.DidYouKnow?Listentotheconversationandchoosethetruestatements.1

Beesareveryimportanttoourfoodsupplybecausetheyprovidehoney.2

Thebeepopulationisdeclining.3

Withoutbees,humanswoulddieout.4

Allhumancropsdependonbeesforpollination.5

Ifbeesbecameextinct,otherinsectscouldpollinateenoughcrops.6

Humansarer