課件英語選擇性必修二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作形式賓語條件真正的賓語是有賓語補(bǔ)足語不定式動名詞從句具備了這兩個條件，形式賓語it一定要用。it作形式賓語的常見情況歸納如下：1.it代替不定式短語。常用于：think/find/feel/consider/make/regard...it+adj./n.+todoIfinditpleasanttoworkwithhim.Theyfeltitdifficulttofinishtheworkinsuchashorttime.Shethinksitherdutytohelphim.Allthesenoisesmadeitimpossibleformetogoonwiththework.2.it代替v.-ing只限于少數(shù)句型。

consider/think/find...it+good/use/worthwhile...+doing...Theprofessorconsidersitnogoodreadingwithoutunderstanding.Doyouconsideritanyusearguingwithhim?Idon’tthinkitworthwhilegoingtosuchaplace.it作形式賓語的常見情況歸納如下：3.it代替賓語從句(that有時候可以省略)。think/find/make...it+n./adj.+ObjectClause...Weallthoughtitapitythattheconferencewascancelled.Theykeptitquietthathewasdead.Hehasn’tmakeitclearwhenheiscomingback.it作形式賓語的常見情況歸納如下：it作形式賓語還有幾種特殊情況，歸納如下：動詞+it+that從句，常見于put,have,take等動詞后。Itakeitthathewillfinishthetaskbyhimself.動詞+it+when/if從句，常見于appreciate,enjoy,like,prefer等動詞之后。Wereallyappreciateitifyoucoulddousafavour.Weoweittoyouthatwearestillalive.Itookitforgrantedthattheywerenotcoming.動詞+it+介詞短語+that從句，常見于oweittosb,takeitforgranted等結(jié)構(gòu)中。動詞+介詞+it+that從句，常見于lookto,dependon,insiston,stickto,answerfor等結(jié)構(gòu)中。Sheinsistedonitthatshewasinnocent.Youmaydependonitthathewillhelpyou.Hemadeitknowntoeveryonethathewasright.Theyhaven’tmadeitknownwheretheyaretoholdtheconference.動詞+it+過去分詞+從句。根據(jù)括號內(nèi)的漢語提示并用it作形式賓語補(bǔ)全下面句子。1._______________________(我認(rèn)為那很重要)tofindapart-timejob.2._______________________________(新技術(shù)使之成為可能)toachieveabalancebetweeneconomicdevelopmentandecosystems.3._______________________(他們覺得很困難)torecovertheoriginalecosysteminsuchashorttimelastyear.4.______________________________________(你為何不讓人們引起注意)thatouractions,nomatterhowsmalltheymaybe,makeadifferencetonature?IconsideritimportantNewtechnologiesmakeitpossibleTheyfeltitverydifficult

Whydon'tyoubringittopeople'sattentionRewritetheunderlinedpartsusingitasanemptyobject.manypeoplethinkitagoodideatokeepthisturtleasapetbelieveitnobigissuetoreleasethemintothewildpeoplehavefounditathreattootherspeciestoreleasetheseturtlesintothewildExpertsconsideritimportantforownerstokeeptheirpetsinanenclosedareaLookatpicturesofSaihanbaNationalForestParkandfindoutthechanges./LocatedinChengdeCity,HebeiProvince,Saihanba(塞罕壩)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