外研版高中英语必修三 （Disaster and hope）SectionB 新课件

Unit6Disasterandhope

SectionBⅠ.知识体系图解

forecastgrabreliablerescueemergencytyphoonblizzardexceptionallyclaimcrisisthreatensatelliteprecisely在路上;在旅行中朝……进发多达作为……而出名尽可能远引起;导致导致多于;超过随着时间的过去注意确保承受;遭受省去;遗漏;不考虑Ⅱ.释义匹配1.forecast A.toanexceptionaldegree2.reliable B.thatcanbetrustedtodosthwell;thatyoucanrelyon3.exceptionally C.topredictinadvance4.claim D.tobeadangertosth5.threaten E.demandasbeingone’sdueorproperty答案:1.C

2.B

3.A

4.E

5.DⅢ.用省略结构完成句子1.当我走在街上时,我听到有人叫我的名字。While

,Iheardmynamecalled.

2.这就是为什么我能让人们的日子更美好。如果你不知道,谁会说另一个人会呢?That’swhyIhelpbrightenpeople’sdays.Ifyou

,who’stosaythatanotherpersonwill?

3.如果被录用,你很快就会得到通知。

forthejob,you’llbeinformedsoon.

4.如果我知道日程安排的话,可能会省去一些麻烦。Itmighthavesavedmesometrouble

theschedule.

walkingalongthestreetdon’tIfacceptedhadIknown重点词汇重点句式重点语法1.on

the

way在途中;即将到来【课文原句】Unusualanimalbehaviour,forexample,canindicatewhetherit’scold,wetweatherthat’son

the

wayorahot,dryperiod.例如,不寻常的动物行为,可以表明即将到来的是寒冷潮湿的天气,还是炎热干燥的时期。【词汇精讲】ontheway在该句子中表示“即将到来”,同时,它还有“在路上”的含义。后面常加to+地点,表示“在去……的路上”。It’sannouncedthatahurricaneison

the

way.通知说飓风即将到来。重点词汇重点句式重点语法【词汇拓展】onthewaytosp在去某地的路上onthewayhome/here/there回家/来这儿/去那儿的路上intheway妨碍;挡道bytheway顺便问一下inaway在某种程度上On

the

way

toschool,Itoldmyfathereverythingthathappenedyesteday.在去学校的路上,我告诉父亲昨天所发生的一切事情。Fredtriedtogettothedoor,butthetablewasin

the

way.弗雷德试图走近大门,可是桌子挡住了去路。IsawTomyesterday.By

the

way,hetoldmethathewouldgotoBeijing.我昨天看见汤姆了。哦,对了,他告诉我他要去北京。重点词汇重点句式重点语法重点词汇重点句式重点语法2.reliable

adj.可信赖的,可靠的【课文原句】So,foraccurateandreliablepredictions,it’sbesttocheckanofficial,scientificreport.所以,为了准确可靠的预测,最好检查一份官方的科学报告。【词汇精讲】reliable为形容词,表示“可靠的”。它的动词为rely,表示“依赖,依靠”。Shepreparesreliablemovestouseifanewsituationarises.她把在新情况下能用得上的可靠动作准备好。重点词汇重点句式重点语法【词汇拓展】relyonsbtodosth依靠某人做某事relyon(doing)sth依赖/信任/指望……relyonitthat...相信……,指望……Nowadaysthechildrenrelymoreontheirparentstodo/doingeverythingforthem.现在孩子们更多地依靠父母为他们做每件事。Youmayrely

on

it

thattheworkwillbefinishedaheadoftime.你可以放心,这项工作将提前完成。【名师点津】下列句型中也要用it作形式宾语:dependon/seetoit+that从句;appreciateit+if从句;like/hateit+when从句。重点词汇重点句式重点语法重点词汇重点句式重点语法3.consist

of由……组成【课文原句】Consisting

of62people,itnotonlyincludedrescuersandmedicalstaff,butalsoincludedearthquakeexperts.它由62人组成,不仅包括救援人员和医务人员,还包括地震专家。【词汇精讲】consistof表示“由……组成”,不用于进行时态和被动语态,但是可以用其动词-ing形式作定语。Theworldconsists

ofsevencontinents.世界是由七大洲组成的。重点词汇重点句式重点语法【词汇拓展】同义短语:bemadeupof;becomposedof由……组成consistin(=liein)在于;存在于consistwith与……一致/相符consistentadj.相容的;一致的beconsistentwith...和……一致;相符Ifwhatyousayisnotconsistent

withwhatyoudo,itwillhaveabadeffectonyourchildren.如果你言行不一,这将对你的孩子有不好的影响。Thebeautyoftheplanconsists

initssimplicity.这个计划妙在简明扼要。【名师点津】由consist组成的几个短语consistof/in/with都不能用于被动语态和进行时态。重点词汇重点句式重点语法重点词汇重点句式重点语法重点词汇重点句式重点语法4.up

to

多达,直到,胜任,由……做决定【课文原文】Whenithitthecoast,hugetidalwavescausedsevereflood,costingthelivesofup

to300,000citizens.当海啸袭击海岸时,巨大的海啸造成了严重的水灾,造成多达30万人丧生。【词汇精讲】在该句子中upto表示“多达”,此外,upto还有“直到,胜任,由……做决定”之意。Ifyouadvertiseyourgoodsinadishonestway,youwillbefinedup

to50,000yuan.如果你不诚实地做广告,你将被罚款多达5万元。重点词汇重点句式重点语法【词汇拓展】Itisuptosbtodosth由某人决定做某事;做某事是某人的职责liveupto符合(期望);不辜负addupto加起来共计lookupto尊重uptonow迄今为止uptodate最新的—Whatshallwedotonightthen?——我们今天晚上做什么呢?—It’sup

toyou—whateveryouwant.——你来决定,你想做什么都行。It’sup

tometoorganizesomewonderfulsinginganddancingperformancesforthem.为他们组织一些精彩的歌舞演出是我的职责。重点词汇重点句式重点语法重点词汇重点句式重点语法重点词汇重点句式重点语法5.threaten

v.

威胁到,危及【课文原句】Itledtoaseverefoodcrisisandthreatenedthelivelihoodsofmorethan9.5millionpeople.它导致了严重的粮食危机,并威胁到950多万人的生计。【词汇精讲】threaten为及物动词,表示“威胁,危及”,还有“恐吓”之意。Theybrokemywindowsandthreatenedme.他们打碎我的窗子并威胁我。重点词汇重点句式重点语法【词汇拓展】threatensbwithsth用……威胁某人threatentodosth威胁/扬言要做某事threateningadj.

危险的;胁迫的;凶兆的threatn.威胁,恐吓;凶兆Theterroristthreatenedthegovernmentwithabomb.恐怖分子用炸弹威胁政府。Officialsattheschoolsaytheyreceivedabombthreatatapproximately11:30a.m.today.学校的官员说他们在今天上午11点半左右收到过炸弹恐吓。重点词汇重点句式重点语法重点词汇重点句式重点语法By

early

May,emergency

aid

worth

9.7

million

US

dollars

had

been

donated

by

China,with

a

further

round

of

emergency

aid

to

follow.到5月初,中国捐赠了价值970万美元的紧急援助,随后还将提供另一轮紧急援助。【句式剖析】该句子为“by+过去时间”引导的时间状语从句,主句用过去完成时,表示“到……时,已经……”。By

the

end

of

last

year,anothernewgymnasiumhadbeencompleted.到去年年底,又有一座新体育馆竣工了。重点词汇重点句式重点语法【句式拓展】(1)by+现在时间,和现在完成时连用(2)by+过去时间,和过去完成时连用(3)by+将来时间,和将来完成时连用Hehastaughtinourschoolfor3yearsby

now.到现在为止,他在我们学校教学3年了。YouwillhavereachedShanghaiby

this

time

tomorrow.明天这个时候你将到达上海。重点词汇重点句式重点语法重点词汇重点句式重点语法省略无论在口语中还是在书面语中,有时为了讲话简洁或行文方便,常常在不影响文意的情况下将句子中的某些成分略去,这种现象称为省略。一、简单句中的省略(一)省略主语祈使句中主语通常省略;其他省略主语多限于少数现成的说法。1.(I)Begyourpardon.2.(I)Thankyouforyourhelp.(二)省略主谓或主谓语的一部分1.(Thereis)Nosmoking.2.(Willyou)Haveasmoke?重点词汇重点句式重点语法(三)省略作宾语的不定式短语,只保留to,但如果该宾语是动词be或完成时态,则须在之后加上be或have:1.—Areyougoingthere?—Yes,I’dliketo(gothere).2.—Hehasn’tfinishedthetaskyet.—Well,heoughttohave.(四)省略表语1.—Areyouthirsty?—Yes,Iam(thirsty).2.Hisbrotherisn’tlazy,norishissister(lazy).(五)同时省略几个成分1.Let’smeetatthesameplaceas(wemet)yesterday.2.—Haveyoufinishedyourwork?—(Ihave)Not(finishedmywork)yet.重点词汇重点句式重点语法二、主从复合句中的省略(一)主句中有一些成分被省略1.(I’m)Sorrytohearyouareill.2.(It’sa)Pitythathemissedsuchagoodchance.(二)状语从句的省略原则主要是:如果从句中的主语和主句中的主语一致,就可以经过一定的变动把状语从句中的主语和谓语的一部分或全部省略,从而使语言更加简洁、明了。现在就把各种状语从句的省略现象列举如下:When(shewas)veryyoung,shebegantolearntoplaythepiano.她很小时就开始学习弹钢琴。Don’tcomeinuntil(youare)askedto.不叫你请你不要进来。重点词汇重点句式重点语法Whenever(itis)possible,youshouldcomeandhelp.不管什么时候只要有可能就来帮忙。注意:as在引导时间状语从句时,没有这种省略现象。(三)不定式符号to的省略1.并列的不定式可省去后面的to。Itoldhimtositdownandwaitforamoment.我告诉他坐下等一会儿。2.help当“帮助”讲时,后面的宾语或宾语补足语的不定式符号to可带可不带。Iwillhelp(to)doitforyou.我会帮你做的。3.but前若有动词do,后面的不定式不带to。Theboydidnothingbutplay.这个男孩除了玩什么也没做。重点词汇重点句式重点语法4.某些使役动词(let,make,have)及感官动词(see,watch,hear,notice,observe,feel,lookat,listento等)后面作宾语补足语的不定式一定要省去to,但在被动语态中须将to复原。Isawtheboyfallfromthetree.我看到这个男孩从树上掉下来了。Theboywasseentofallfromthetree.这个男孩被(我)看到从树上掉下来了。5.主语从句中有动词do,后面作表语的不定式的to可带可不带。Allwecandonowis(to)wait.我们现在能做的就是等。重点词汇重点句式重点语法6.find当“发现”讲时,后面作宾语补足语的不定式符号to可带可不带。Wefoundhim(to)workveryhardattheexperiment.我们发现他在这个实验中工作很努力。但如果是不定式tobe,则不能省略。Shefoundhimtobedishonest.她发现他不诚实。重点词汇重点句式重点语法(四)连词if在部分虚拟条件句中可省略,但后面的语序有变化。1.Hadtheytime,theywouldcertainlycomeandhelpus.如果他们有时间,他们一定会来帮助我们。2.WereIyou,Iwoulddotheworkbetter.如果我是你,我会把工作做得更好。3.Shouldtherebeaflood,whatshouldwedo?如果那里有洪水,我们应该做什么?(五)主句和从句各有一些成分省略。Thesooner(youdoit),thebetter(itwillbe).越快越好。重点词汇重点句式重点语法三、并列句中的省略两个并列句中,后一个分句常省略与前一分句中相同的部分。Myfatherisadoctorandmymother(is)anurse.我父亲是医生,母亲是护士。Istudyatcollegeandmysister(studies)athighschool.我上大学,我妹妹读高中。Whensummercomes,thedayisgettinglongerandlonger,andthenight(isgetting)shorterandshorter.夏天来了,白天越来越长,黑夜越来越短。重点词汇重点句式重点语法四、其他省略(一)连接词that的省略1.宾语从句中常省略连接词that,但也有不能省略的情况。2.在定语从句中,that在从句中作宾语时可省略。另外,凡是进行时态和被动语态的定语从句都可省略关系代词和be动词。(二)在某些状语从句中,从句的主语与主句的主语一致时,可省去“主语+be”部分。When(hewas)stillaboyof10,hehadtoworkdayandnight.Shetriedherbestthough(shewas)ratherpoorinhealth.If(youare)askedyoumaycomein.If(itis)necessaryI’llexplaintoyouagain.ⅠⅡⅢ单词拼写1.Today’sweatherf

isforsunshineandshowers.

答案:forecast2.Ig

herbythearmandtriedtopullheraway.

答案:grabbed3.Trainsare

(rely),cheapandbestforlong-distancejourneys.

答案:reliable4.Thepolicecametohisr

andhewasverythankfulwhenhewassafe.

答案:rescue5.Sheiscalmandresourcefulinan

(紧急事件).

答案:emergencyⅠⅡⅢ6.Ithadbeenan

(极其)difficultwork.

答案:exceptionally7.They’veputina

(要求)forapayrise.

答案:claim8.Naturaldisastershaveobviouslycontributedtothecontinent’seconomicc

.

答案:crisis9.Thenewcomersdirectlyt

thelivelihoodoftheestablishedworkers.

答案:threaten10.Themeetingstartsat2pm

(精确地).

答案:preciselyⅠⅡⅢ翻译句子1.这些问题,如果不妥善处理的话,将严重影响青少年的成长。(ifnotsolvedproperly)答案:Theseproblems,ifnotsolvedproperly,willseriouslyaffectthegrowthofteenagers.2.这个感人的故事如果改编成电视剧,一定会大受欢迎。(ifadapted;ahit)答案:Thismovingstory,ifadaptedfortelevision,wouldbeahit.3.你的建议使我高兴但使汤姆生气。(省略动词)答案:YouradvicemademehappybutTomangry.ⅠⅡⅢ4.这次展览比预料的有趣得多。(thanexpected)答案:Theexhibitionismoreinterestingthanexpected.5.这是一个最多可容纳五个人的房间。(upto)答案:Thisisaroomwhichcanaccommodateuptofivepeople.ⅠⅡⅢ

语法填空LastThursday,therewasabigfireinabigshopinourcity.At8:16thatmorning,1.

theemployeeswereworkingbusilyinthe4-storeyedbuilding,heavysmokewasseen2.

(come)outofthewindowsonthesecondfloor.Thefirelastednearlyanhour,andthemajorityofthe345employeesmanaged3.

(escape)fromthefire.Unfortunately,7werekilled,and23injured,lightlyorseriously.

Someworkers4.

(complain)thataidscametoolate,5.

thefiremendidcomejust10minutesafterthefirewasreported.Torescueeveryonefromtheburningandsmokingbuildinginsuchashorttimewastoodifficult.Theonlytwoexitsofthebigbuildingwerenotenoughforsomanypeopletowithdrawin6.

hurry.

when

comingtoescapecomplainedbutaⅠⅡⅢThereasonofthefire,accordingtoaninvestigator,was7.

someonebrokethenon-smokingruleinthefactory,becausesomecigaretteends8.

(find).Nexttwoweeks,15inspectionteamswillbeworkinginallthefactories9.

turn,aimingtoclearawaythepossibilityofmorefires.10.

(hope),nodisasterslikethiswillhappenagain.

thatwerefoundinHopefullyUnit6Disasterandhope

SectionCⅠ.知识体系图解

billionlapnowhereotherwise

mosquitomidnightcountythreatpropertysufficientshelter还没有飞出,飞走出来转变成一开始上上下下,来来回回尽力/努力做某事继续做某事及时一会儿,半晌远离,回避发生Ⅱ.介(副)词填空1.

average,eachofthetwomillionbigstonesweighedaboutasmuchasalargepickuptruck.

2.Ideterminedtowritethemdown,neverlettingmyselfleave

atoughidea.

3.Colmhadtohavemoretreatment

thewaytothehospitalandwe’vegottoseeanexpert.

4.Thepackedlunchconsists

asandwich,adrinkandadessert.

5.Asisknowntous,itisouractivitiesthatlead

airpollution.

OnoutonoftoⅢ.阅读导学根据pp.68-69课文内容,选出正确答案。1.Wecanlearnfromthefirstparagraphthat

.

A.theauthorwastoofrightenedtoknowwhattodoB.theroofwasjustbrokenalittlefortheauthortoseetheskyC.thehurricanehappeningyearsagowasstrangetotheauthorD.thecatSmartiewassleepingontheauthor’slapbeforethedisaster2.Whichofthefollowingisnotincludedwhenthestormcame?A.Thestreetbecameariverinseconds.B.Thewaterwasfloodedintotheauthor’shouse.C.Theauthor’smothertriedtoleavethehousebutfailed.D.Theauthorhadmosquitoesforbreakfast,lunchanddinner.AD3.Thethirdandfourthparagraphsaremainlyabout

.

A.theeffectofthebigstormontheauthor’sfamilyB.thegreatlossthestormbroughttotheauthor’sfamilyC.howtheauthor’sfamilyspenttheirlifeafterthestormD.thehardlivingconditionoftheauthor’sfamilyafterthestorm4.WhatwasMom’sattitudetowardthedisaster?A.Positive. B.Depressed.C.Pessimistic. D.Grateful.5.Havingexperiencedthestormtheauthorhaslearned

.

A.tobehopefulforthefutureB.tobetogetherwithfamilyC.toinspireotherstomoveonD.togiveconfidencetoeachotherCAA重点词汇重点句式高分写作1.turn

into

变成【课文原句】Ourstreetturned

intoariverinseconds.我们的街道在几秒钟就变成了一条河。【词汇精讲】turninto表示“变成”。IthinkIhavegottostoporImightturn

intoamachine.我想我得停下来了,否则我就会变成一台机器。【词汇拓展】turnaway把(脸)转过去;把……打发走turnaround转过身,转向反方向turndown拒绝;调小(音量)turnoff关掉;使厌烦turnon打开重点词汇重点句式高分写作turnout结果是;证明是turnto求助于;翻到(书的某页);致力于;开始从事;查阅;转向turnup出现;调大(音量)Wecannotunnecessarilyexcuseourselvesorturntheotherpersonoff.我们不能给自己找借口却使别人感到讨厌。Heheardavoicebutwhenheturned

around,hesawnobody.他听到一个声音,但转身却没发现有人。IfIrollmyeyesandturnmyheadaway,ImostlikelydonotbelievewhatIamhearingordonotlikeit.如果我翻眼睛并转过头去,我很可能不相信听到的话或不喜欢这些话。重点词汇重点句式高分写作重点词汇重点句式高分写作2.remind

vt.

提醒;使想起【课文原句】ButasMomkeptonremindingus,wewerealltogetherandsafe.但妈妈一直提醒我们,我们都在一起,很安全。【词汇精讲】remind为及物动词,在此句中表示“提醒”,它还有“使想起”的意思。Iwouldhaveforgottenmybirthdayifyouhadn’tremindedme.要不是你提醒,我把自己的生日都忘了。ItremindedmeofmytimeinSudan.这使我想起了我在苏丹的那段时光。重点词汇重点句式高分写作【词汇拓展】remindsbofsth/doing提醒某人(做)某事remindsbtodosth提醒某人去做某事remindsbthat...提醒某人……remindern.起提醒作用的人或物Iremind

him

thathemustgohomebeforedark.我提醒他必须在天黑前回家。Barbaraoftenmakesascheduletogetherselfremindedofwhatsheistodointheday.芭芭拉经常制定一个时间表来提醒自己一天中应做什么。重点词汇重点句式高分写作重点词汇重点句式高分写作重点词汇重点句式高分写作3.in

time

及时;迟早【课文原句】Thankfully,Smartiecamehomejustin

time.谢天谢地,斯玛蒂及时回家了。【词汇精讲】intime在该句子中表示“及时”的意思,它还有“迟早”之意。Iurgethatallofusformthehabitofthinkingindependentlyandreviewinglessonsin

time.我主张大家应该养成独立思考和及时复习的习惯。重点词汇重点句式高分写作【词汇拓展】intimeforsth及时赶上某事intimetodosth及时赶上做某事ontime按时;准时IwascaughtinatrafficjambutfortunatelyIarrivedin

time

topickupmysonfromschool.我遇上了交通堵塞,然而幸运的是,我及时赶上了接儿子放学。Hedemandedthattheyshouldbethereon

time.他要求他们按时到那儿。重点词汇重点句式高分写作重点词汇重点句式高分写作4.sufficient

adj.足够的,充足的【课文原句】Makesureyouhavesufficientfood,water,medicineandbatteriesforelectricalappliances.确保你有足够的食物、水、药品和电器电池。【词汇精讲】sufficient为形容词,表示“足够的,充足的”。Idoubtwhethertheyreallyhavesufficientmanpower.我怀疑他们是否真有足够的人力。重点词汇重点句式高分写作【词汇拓展】besufficientforsth对于……足够besufficienttodo足够做某事insufficient不够的sufficientlyadv.充分地;足够地Is

￡100sufficient

foryourexpenses?100英镑够你花销吗?Themoneyisnotsufficient

tocovereverythingthatneedsdoing.这些钱不足以支付所有要做的事情。重点词汇重点句式高分写作重点词汇重点句式高分写作5.shelter

n.庇护,掩蔽vt.保护;使掩蔽【课文原句】Ifyoucannotgethomeintime,findothershelterassoonasyoucan.如果你不能及时回家,尽快找到其他的避难所。【词汇精讲】shelter在此句中为名词,表示“避难所”。当表示笼统的避难处的时候,shelter为不可数名词。同时,它还为动词,表示“保护;使掩蔽”。Allaroundme,peoplewererunningforshelter.我周围的人都在寻找地方躲避。重点词汇重点句式高分写作【词汇拓展】seekshelter寻求庇护runforshelter找躲避处takeshelterfrom躲避givesbshelter庇护某人Peopleweredesperatelyseeking

shelterfromthegunfire.人们拼命地找地方躲避炮火。Welookedaroundforsomewheretake

shelter

fromthestorm.我们环视四周,想找个躲避风雨的地方。重点词汇重点句式高分写作重点词汇重点句式高分写作I

was

sitting

in

my

room

with

my

cat,Smartie,on

my

lap,when

the

roof

just

flew

off.我坐在房间里,我的猫Smartie趴在我的腿上,正在这时,屋顶突然飞走了。【句式剖析】该句为“was/weredoingwhen+一般过去时”构成的主从复合句,表示“(过去)……发生时主语正在做某事”。Hewas

on

the

point

of

leaving

whensomeoneknockedatthedoor.他刚要走就有人敲门。重点词汇重点句式高分写作【句式拓展】when用作“这时;突然”的其他结构beabouttodosthwhen...正要做某事突然……beonthepointofdoingsthwhen...正要做某事突然……hadjustdonesthwhen...刚做完某事突然……Wewere

about

tostartwhenitbegantorain.我们刚要出发就开始下雨了。Hehad

justfinishedhishomeworkwhenhismothercameback.他刚做完了作业妈妈就回来了。重点词汇重点句式高分写作重点词汇重点句式高分写作如何写好应用文建设平安校园是我们每个人的责任与义务。作为一名学生,我们更应该珍惜自己的生命,注意自己的人身安全。假如你是李华,并担任校学生会主席,请你就安全问题向全校学生发出倡议,写一封安全倡议书。内容提示:(1)不带管制刀具(restrictedknives)到学校;(2)不打架;(3)上学放学的途中应该注意安全;(4)遇紧急情况,立即报告警察或老师。要求:(1)用词恰当,要点全面;(2)可适当发挥,80词左右。重点词汇重点句式高分写作参考范文:Dearstudents,Whenitcomestolife,safetytakesthemostimportantplace.Therefore,weneedtosparenoefforttoguaranteeoursafety.Firstly,bringingrestrictedknivestoourschoolisnotallowed,fortheyaresodangerousthatmayleadtoinjuryorblood.Secondly,bathinginriversorpondsisonlyacceptablewhenwithanadult.Besides,westudentsaresupposedtogetalongwellwitheachother,whichmeansfightingisabsolutelyforbidden.Furthermore,weshouldalwayswatchoutbothonthewaytoschoolandbackhome.Lastbutnotleast,wheneverthereisanemergency,askhelpfromthepoliceorourteachers.重点词汇重点句式高分写作Onlybyfollowingalltherulesabovecanwekeepourselvessafeandsound.ThePresidentoftheStudents’UnionLiHua重点词汇重点句式高分写作一、审题定调1.确定体裁:该习作要求就安全问题,向全校学生发出倡议,写一封安全倡议书,是应用文题材中的倡议书的写作。2.确定人称:人称以第一人称为主。3.确定时态:时态以一般现在时为主。二、谋篇布局倡议书必须写清楚三点:一是倡议做什么事?二是为什么要倡议做这些事?即讲清目的和意义。三是怎么去做,提出初步设想。就本篇习作而言,我们可以把全文分为三部分。第一部分:引出话题,阐明观点(安全很重要);第二部分:说明倡议的内容;第三部