Unit2HealthylifestyleDiscoverUsefulStructures課件高二英語人教版選擇性

人教選擇性必修第三冊Unit2DiscoverUsefulStructures12Tounderstandthefunctionandmeaningofinfinitivesusedassubjects

Tolearnhowtouseinfinitivesassubjectsinaspecificcontext目標一：TounderstandthefunctionandmeaningofinfinitivesusedassubjectsActivity1:Lookatthefollowingsentencesandpayattentiontotheitalicisedinfinitives.Inpairs,discusstheirfunctions.=It’snevereasytochangebadhabits.1.Tochangebadhabitsisnevereasy.2.Ittookthesurgeon(n.外科醫(yī)生)threehourstofinishmymother’slungsurgery(n.外科手術(shù)).3.Tojoin

thePeople’sLiberation(n.解放)Army,itisrequiredformentoshaveoff(剃掉,刮掉)theirbeards.4.Itwasnotpolitetodisturb(v.打擾)yourneighbourswithloudmusiclastnight.主語主語主語主語四個句子中的不定式都充當主語。用形式主語it代替真正的主語tochangebadhabits符合英語表達習慣，避免句子頭重腳輕、結(jié)構(gòu)失衡。如果作者有意將比較長的不定式主語放在句首，那么作者就是想要突出不定式的內(nèi)容。Activity2:Find

moreinfinitivesassubjectsinthereadingpassage.Thendiscusstheirmeaningsandfunctionsingroups.1.However,duringthisperiod,itcanbeeasyforsomeofthemtoformbadhabits.2.Topreventharmfulhabitslikethesefromdominatingateenager’slife

isessential.3.Tochangebadhabitsisnevereasy,evenwithmanyattempts.4.Afterall,itisnoteasytobreakbadhabits.2.作主語的動詞不定式在句中的位置：(1)不定式置于句首。e.g.Togettherebybikewilltakeushalfanhour.Tomakeupforlosttimeisnotpossible.動詞不定式做主語1.動詞不定式作主語時，句子的謂語動詞常用單數(shù)。e.g.Toleanoutofthewindowisdangerous.

Tosavemoneynowseemsimpossible.

Thinkitback:句中for與of的區(qū)別在哪？◎It+be+adj.+for/ofsb.+todoItis＋adj.

＋forsb.todosth.常用于表示事物的特征，用于此句型的形容詞有：easy,hard,difficult,possible,important,impossible,necessary,good,bad,exciting,interesting,surprising等。Itis＋adj.＋ofsb.＋todosth.表語常為表示人的性格、品質(zhì)的形容詞，句中用of。如good,kind,nice,foolish,polite,ever,careless等。3."疑問詞+動詞不定式（短語）"結(jié)構(gòu)動詞不定式（短語）可與疑問詞when,where,how,what,which,who等組合，在句中作主語。e.g.Wheretoholdthemeetingisstillunknown.

Howtosolvetheproblemhasnotbeendecidedyet.Activity3:Findothersentenceswithinfinitivesinthereadingpassageandsortthem.目標二：Tolearnhowtouseinfinitivesassubjectsinaspecificcontext

Activity1:Jointhewordstomakefullsentences,andthenjointhe

sentencestomakeaparagraph.Youcanaddyourown

sentencesifnecessarytomakeyourparagraphmore

meaningful.Example:1.important/avoid

/passivecigarettesmoking

Itisimportanttoavoidpassivecigarettesmoking.2.willtake/nutritionspecialist/abalanceddietmenu/make/anhour/

foryou_____________________________________________________________3.useful/turnto/fitnessconsultant/foradvice_____________________________________________________________4.illegal/dangerous/take/drugs_____________________________________________________________5.harmful/skipbreakfast/often_____________________________________________________________Itwilltakenutritionspecialistanhourtomakeabalanceddietmenuforyou.Itisusefultoturntofitnessconsultantforadvice.Itisillegalanddangeroustotakedrugs.Itisharmfultooftenskipbreakfast.Activity2:Completetheconversationswiththecorrectformsofthephrasesinthebox.beginwithbeincontrolofmakeachoicedecideonmakeupone'smind1A:Hello,doctor.Iwanttoloseweight,butIjustcan’tseemtodoit.

What

canyoudotohelpme?

B:Well,first,it’snecessaryto_____________whatyoueat.Cutoutall

fattyfoodand

sugarydrinks,andeatmorefruitandvegetables.2A:

Ireallyneedto

_________awaytoexercisemore.Icouldusea

fitnessapp,butmyphone’sfull.B:Sodeleteafewfiles.I'msuretheappdoesn'ttakeupmuchspace.decideonbeincontrolof

3A:Beforeexercising,alwaysdoafewwarm-upsto__________.

B:Iknow.ButthenIalwaysfeeltootiredtocontinue!4A:ShouldIgoforthepizzaorthefriedchicken?Ihate

______________likethese.Youknowwhat—I'mgoingtoeatboth!

B:Wow!Don’tea