人教版（2019）選擇性必修第三冊Unit 2 Health lifestyle Healthy lifestyle Discover useful structures 課件

UNIT2HEALTHYLIFESTYLEInfinitivesasthesubject

Discoverusefulstructures1.However,duringthisperiod,itcanbeeasyforsomeofthemtoformbadhabits.2.Topreventharmfulhabitslikethesefromdominatingateenager’slifeisessential.3.Tochangebadhabitsisnevereasy,evenwithmanyattempts.4.Afterall,itisnoteasyto

breakbadhabits.5.Whentoholdthesportsmeetinghasnotbeendecided.ObserveandDiscoverLookatthefollowingsentencesandpayattentiontotheinfinitives.P36【語法感悟】①在句1、4中，it是

，代替后面的動詞不定式短語。

②在句2、3中，Toprevent...和Tochange...都是動詞不定式短語作

________。

③在句5中，Whentohold...是“疑問詞+todo”結(jié)構(gòu)，該部分在句中作

。

形式主語

主語

主語

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總結(jié)

思考

位置

含義

本質(zhì)

名詞詞性

不定式短語在句中做主語。一【含義】

不定式作主語一般表示具體的或某一次的或?qū)淼膭幼?謂語動詞用單數(shù)。To

knowsomethingaboutEnglishisonething;to

knowEnglishisquiteanother.懂一點英語是一回事；掌握英語完全是另一回事。注：單個不定式作主語時，謂語用單數(shù)形式；兩個及以上不定式作主語時，謂語用復(fù)數(shù)形式；但作為一個整體時，謂語用單數(shù)形式。Wheretogoonaholidayandwhentogofortheholiday_____(have)notbeendecided.Whereandwhentogoonaholiday______(have)notbeendecided.havehas不定式作主語，有時根據(jù)表達的需要，可以在添加疑問代詞或副詞，疑問代詞：who，whom，what，which疑問副詞：when，where，howwhetherE.g.Howtobreakthebadhabit

isthequestion.Wheretogo

hasn'tbeendiscussed.It

hasnotbeendecided

whethertoflytoParis.

”疑問詞+todo”作主語【Practice】Usethecorrectformsofthewordstofillintheblanks.When________(start)hasnotbeendecidedyet.How________(use)thecomputeristhequestion.Ithasbeendecidedwhere________(spend)ourwinterholiday.tostarttousetospend二【位置】1.Topreventharmfulhabitslikethesefromdominatingateenager'slife

isessential.2.Tochangebadhabits

isnevereasy,evenwithmanyattempts.3.Afterall,itisnoteasytobreakbadhabits.4.However,duringthisperiod,it

canbeeasyforsomeofthemtoformbadhabits.

句首it作形式主語,不定式放句尾考點二：it作形式主語常見的句型1.Itis+形容詞+for/ofsb+todosthE.g.Itiseasyformetolearnhowtodrive.Itiscleverof

youtoapplyfortheposition.一般規(guī)律：若形容詞”描述人的屬性，特征”,用of;若形容詞“描述事或物的特征”,

用for;2.Itis+名詞(apleasure/apity/anhonour...)(forsb)+todosthE.g.Itisanhonourtogiveaspeechinbehalfofmyschool.Itisapitytomissthechancetoseeyourshow.3.It

takes/took/willtakesb.sometime/moneytodo

做某事花費,某人多長時間(錢)E.g.Ittookmemorethananhourtodo

myhomeworkyesterdayevening.?

?完成句子①Itseemedselfishofhim

nottogivehisemployeesanything

?.

他不給員工任何東西，這顯得他太自私了。②Itseemsapity

torefusetheinvitation

?.

拒絕這份邀請似乎是遺憾的。③It’sunwise

ofthemtoturndowntheproposal

?.

他們拒絕（采納）這個建議是不明智的。④Itwillbeamistake

forusnottohelpthem

?.

我們不幫助他們將是錯誤的。nottogivehisemployeesanything

torefusetheinvitation

ofthemtoturndowntheproposal

forusnottohelpthem

Itwilltake

thenutritionspecialistanhourtomake

abalanceddietmenu

foryou.Itisusefultoturn

tothefitnessconsultantforadvice.Itisillegalanddangerousto

takedrugs.Itisoftenharmfulto

skipbreakfast.拓展1：it作形式主語,doing作真正的主語1.浪費時間做某事:2.做某事是沒有用的：

3.做某事是沒有樂趣的：

4.做某事是沒有好處的：Itisawasteoftime

doingsthIt'snouse

doingsthItisnofun/pleasure

doingsthItisnogood

doingsth拓展2：todo和doing作主語的區(qū)別Tolookafterchildrenisherjobtoday.

她今天的工作是看孩子。Lookingafterchildrenisherwork.

她的工作是照顧孩子。區(qū)別todo通常表示一個將來的、具體的內(nèi)容;

(動作)doing而則表示一種經(jīng)常性的、習(xí)慣的或抽象的概念。(事情)?

?單句語法填空①

Tohear

?

（hear）yourvoiceissonice.

②

Tolook

?

（look）afterthesafetyofthecommunityishisresponsibility.

③

Smoking

?

（smoke）isprohibitedhere.④How

tocure

?

（cure）thiskindofillnessisstillunknown.

Tohear

Tolook

Smoking

tocure

beincontrolofdecideonbeginwithmakingchoicesmadeupmymindHowcanweloseweight?todo作主語todo作主語位于句首,謂語動詞用單數(shù)it作形式主語疑問詞+todo構(gòu)成不定式短語和-ing作主語的區(qū)別Toreadwithoutreflectingislikeeatingwithoutdigesting.Ittakessb.time/moneytodosth.Itis+adj.+(for/ofsb.)todosth.Itis+n.+(forsb.)todosth.todo表示具體的，將來的動作-ing表示一般的，已經(jīng)完成的動作與疑問詞who,whom,whose,what,which,when,where,how等連用

Summary1A:I'mthinkingaboutridingamotorbiketoschool.Whatdoyouthink?B:Oh?Well,Ithinkit'snecessary________________________________first.2A:Howcomeyoufaintedsuddenlyyesterday?Didn'tyoueatanythinginthemorning?B:I'monadiet.A:That'ssobad!Youknowit'simportant_____________________everymorning.3A:IoftenseeyouaroundCentralPark.B:Yes,Ilike_______________________thereeveryweekend.Weusuallyplayballgames.4A:Ihearthatthenewheadmasterhastoomanythingstodo.B:Yes.Itwillbeabigchallengeforhim_____________________________________.Agroupofstudentsarechattingafterclass.Completetheconversationswiththecorrectformsofthephrasesinthebox.eatagoodbreakfastgetyourparents’permissionhangoutwithfriendsbalanceworkandpersonallife

togetyourparents’permissiontoeatagoodbreakfasthangingoutwithfriendstobalance（his）workandpersonallife(WORKBOOKP69EX.1)Itwilltakeusabouthalfanhour________________（到達）theWestLake.Inthemorning,wewillvisittheplacesofinterestaroundorneartheWestLake,includingthelake,GuHill,Lingyin