沪教版八年级下册英语Unit8科幻外星because原因状语从句语法课件（可编辑完整版）

主题范畴：人与自然；人与社会主题群：宇宙探索；历史、社会与文化子主题：地球与宇宙探秘，航天事业发展；中外文学史上有代表性的作家和作品Setion2GrammarVolunteersNeeded!Review

spaceshipastronautrocketUFOalien[ˈspeɪsʃɪp]太空飞船[ˌju:ef'əʊ]不明飞行物[ˈrɒkɪt]火箭[ˈæstrənɔ:t]宇航员[ˈeɪliən]外星人Lead-inLookandfindWewenttherebecauseIheardaloudnoiselastnight.(P118)Sincenooneelsesawthesealiens,Irefusetobelieveyou.(P117)I’msuresomethinglandedintheforestnearthehillsasIheardaloudnoiselastnight.(P117)because、since和as

可以引导原因状语从句。Havealook1.HedistrustedmebecauseIwasnew.2.Asalltheseatswerefull,hestoodup.3.Since/Aswehavenomoney,wecan’tbuyit.4.Thechildrenwokeupbecauseofaloudnoise.5.Iwaslatebecauseoftheheavytraffic.While-learningP121GrammarAdverbialclausesofreason原因状语从句Adverbialclausesofreasontelluswhythingshappen.原因状语从句告诉我们事情发生的原因。Readthesummaryofthestoryonpage117.Payattentiontothewordsinbold.Thenanswerthequestions.Answerthequestions.(1)Whywastherealoudnoiselastnight?(2)Whycouldn’tthespaceshipfly?Therewasaloudnoisebecause

aspaceshipcrashedintheforest./

Because

aspaceshipcrashedintheforest,therewasaloudnoise.Becauseof

thedamage,thespaceshipcouldn’tfly./Thespaceshipcouldn’tflybecauseof

thedamage.Whendoweusebecause/as/since?

Whendoweusebecauseof?Whendoweuseacomma(,)?_______Let’ssumuptherules!Weusuallyusebecause,asandsincetointroduceadverbialclausesofreason.

As/Because/Sincenooneelsesawthesealiens,Irefusetobelieveyou.Wecanputtheadverbialclauseofreasoneitherbeforeorafterthemainclause.

Irefusetobelieveyouas/because/sincenooneelsesawthesealiens.我们通常使用because、as和since来引导原因状语从句。原因状语从句既可放置于主句之前也可放置于主句之后。Whenweputtheadverbialclauseofreasonatthebeginningofthesentence,weoftenseparateitfromthemainclausewithacomma(,).Wecanalsousebecauseoftogivethereasonforsomething.Wecanuseanoun,anounphraseoranobjectpronounafterbecauseof.注意!当原因状语从句位于句首时，通常用逗号将其与主句隔开。我们也可以用becauseof来说明某事的原因。becauseof后可接名词、名词短语或宾语代词。Whenweusebecause,weputemphasisonthereason.Itisoftenusedtoanswerthewhyquestion.—WhydidColumbussailwest?—

Because

hewantedtofindanewtradingroutetoAsia.Weoftenuseasandsincetolaymoreemphasisontheresultthanthereason.Ihopethey’vedecidedtocome

as/

since

lwantedtohearabouttheirAntarcticatrip.Arebecause,sinceandasusedinthesameway?Whatisthedifferencebetweenbecause,sinceandaswhenexpressingreasons?Let'slearnmore!becausebecause表示直接原因，其语气最强。常用来回答why的提问，常用于引导原因状语从句。①MrGreendidn’tcomebecauseitwasrainingheavily.

因为下大雨，格林先生没有来。②

BecauseLinglingwasill,shedidn’tcometoschool.

玲玲因病，没有上学。③—Whyissheabsent?—Becausesheissick.

—她为什么缺席？ —因为她病了。because引导的原因状语从句有时可以与带有becauseof短语的句子互换。注意:

because习惯上不能与so连用。sincesince也可以用来引导原因状语从句，表示显然的或已为人知的理由，常译为“因为；既然”。①

Sinceheasksyou,youjusttellhimwhy.

他既然问你，那就告诉他为什么吧。②

Sinceeveryoneishere,let’sstart.

既然大家都到齐了，我们就出发吧！③

SinceIunderstoodverylittleJapanese,Icouldn’tfollowtheconversation.

我日语懂得不多，因而听不懂对话。asas表示的“原因”是双方已知的事实或显而易见的原因，或者理由不是很重要，含义与since相同，但语气更弱，常译为“由于；鉴于”。①

AsIhadacold,Iwasabsentfromschool.

由于感冒，我没去上学。②

Asitwasgettinglate,Idecidedtobookintoahotel.

由于天色已晚，我决定找家旅馆投宿。becauseof①Hecan’tgotoschoolbecauseof

sickness.

他因病不能上学。②Iwenttothepartybecauseof

him.

因为他，我去参加了聚会。③Thisboydidn’tdohishomeworkbecauseof

skating.

这个男孩因为滑冰而没有做家庭作业。becauseof也可以用来说明原因，但它的后面通常跟名词（短语）、代词或V-ing形式等。because与becauseof的区别because和becauseof的意思都是“因为”，其区别为：1.because后面接从句；2.becauseof后面接名词或名词短语。请对比：因为下雨，他们没去博物馆。Theydidn’tgotothemuseumbecauseitrained.(itrained是句子)Theydidn’tgotothemuseumbecauseoftherain.(therain是名词)Let'ssummarize!一、原因状语从句连词用法说明：连词用法说明because表示直接、明确的原因。常用于回答以“why”开头的疑问句。since表示显而易见的原因，常译为“既然；鉴于”。as表示双方都知道的原因，多用于口语中，常译为“由于”。类别连接词/结构语法功能语气与位置特点例句原因状语从句because/as/since后接完整句子because强调直接原因（用于回答Why引导的问句）；as/since侧重已知前提。从句位于主句之前时，需加逗号；从句位于主句之后时，无需逗号。—Whywastherealoudnoise?—Becauseaspaceshipcrashed.Becauseaspaceshipcrashed,therewasaloudnoise./Sincenoonesawthealiens,theirfatherrefusedtobelievethem.续表：类别连接词/结构语法功能语气与位置特点例句表原因的短语becauseof后接名词(短语)或代词表原因，不可接完整句子。Thespaceshipcouldn’tflybecauseofthedamage.Let'spractise!ThepoliceofficeraskedTomsomemorequestionsaboutthealiens.Matchthequestionswiththeanswers.Thenusethemtocompletetheofficer'snoteswithas,since,becauseorbecauseof.Remembertowritecompletesentences.Check!P122Policeofficer'snotesP122(1)(becauseof)____________________________________________________________________________________(2)(because)______________________________________________________________________________________(3)(as)___________________________________________________________________________________________(4)(Since)________________________________________________________________________________________Tinawassurethatsomethinglandedintheforestnearthehillsbecauseofaloudnoiselastnight.TinaandTomhidbehindsomebushesbecausetheyheardsomevoicesspeakingastrangelanguage.TinaandTomranawayasanaliensawthemandmadeaterriblenoise.Sincenooneelsesawthesealiens,TinaandTom’sfatherrefusedtobelievethem.Post-learningDoyouthinkaliensexist?Whyorwhynot?Readthenewsheadlinesanddiscussthequestionsinpairs.Usebecause/as/since/becauseoftocombinethesentences.(1)Thelakewasdangerous.Theyavoidedit.(because)(2)Therewasalotofsmoke.Itwasdifficulttoseeanything.(Becauseof)Theyavoidedthelakebecauseitwasdangerous.Becauseofthesmoke,itwasdifficulttoseeanything.(3)Wehavelostourmap.Wehadbetteraskfordirections.(Since)(4)Thespaceshipcouldn’tland.Theweatherwastoobad.(because/becauseof)Sincewehavelostourmap,wehadbetteraskfordirections.Thespaceshipcouldn’tlandbecausetheweatherwastoobad.Thespaceshipcouldn’tlandbecauseofthebadweather.一、从括号中选择适当的词或词组填空。1.Wewenttothenewbookshop__________(because/becauseof)thebookstherewerecheaper.2.__________(after/since)it’sasecretplan,youcan’ttellanyoneaboutit.3.__________(as/until)themathstestwassimple,allthestudentsinYangRui’sclasspassedit.4.__________(because/becauseof)thebadweather,theGreenshadtostayathomeallday.5.Theboyhid