北师大版高一英语必修二课件：unit6-Design-Lesson-1

Lesson1Lesson11Lookatthepictures,whichdoyoulikebest?Why?BeforeyoustartLookatthepictures,whichdo2北师大版高一英语必修二课件：unit6-Design-Lesson-13WordsPreviewexhibitionpoetrymissilemaneshadesweatyouthn.展览会n.诗（总称）n.导弹n.鬃毛n.阴影，阴暗处n.汗n.青春，年轻人WordsPreviewexhibitionn.展览会4insectfixone’seyesoncreatureartistvaluabletypicalelegantlyWordsPreviewn.昆虫注视，凝视n.动物，人n.艺术家，画家adj.贵重的，有价值的adj.典型的adv.优美地insectWordsPreviewn.昆虫5emphasisedetailclothfoldshallowshoreeyesightWordsPreviewvt.强调n.细节，详情n.布，布料n.褶皱adj.浅的n.岸边n.视力emphasiseWordsPreviewvt.强调6Learnsomethingmoreaboutthepaintersoftheseworks,getmoreinformationofthesegreatartists.Learnsomethingmoreaboutthe7北师大版高一英语必修二课件：unit6-Design-Lesson-18齐白石（1864－1957），湖南湘潭人，二十世纪中国画艺术大师，二十世纪十大书法家,画家之一，世界文化名人。齐白石（1864－1957），湖南湘潭人，二十世纪中国画艺术9北师大版高一英语必修二课件：unit6-Design-Lesson-110北师大版高一英语必修二课件：unit6-Design-Lesson-111徐悲鸿(1895-1953),是兼采中西艺术之长的现代绘画大师,前驱式的美术教育家。徐悲鸿(1895-1953),是兼采中西艺术之长的现代绘画大12北师大版高一英语必修二课件：unit6-Design-Lesson-113北师大版高一英语必修二课件：unit6-Design-Lesson-114陈逸飞(1946-2005)生于宁波，浙江镇海人。1984年，美国《艺术新闻》杂志将陈逸飞定名为“一个浪漫的写实主义者，作品流露强烈的怀旧气息，弥漫其中的沉静与静寂氛围尤其动人。”陈逸飞(1946-2005)生于宁波，浙江镇海人。198415北师大版高一英语必修二课件：unit6-Design-Lesson-116Readthetextsandcompletethenotes.PlaceDatesArtistsPaintingsNewmanGallery,Dinham1Julyto15SeptemberXuBeihong,QiBaishiandChenYifeiRacingHorse,CabbageandPoppy2Readthetextsandcompleteth17SubjectsofpaintingsColoursusedahorserunningathighspeed;atinyinsectfixingitseyesonthecabbagenearby;

ayoungwomansittingalone,deepinthought,herhandholdingthefanaboveherknees

black,grey,dark,lightSubjectsofpaintingsColoursu18ReadingExhibition:ChinesePrintsXuBeihongQiBaishiChenYifeiRacingHorseCabbagePoppyReadingExhibition:ChinesePri19Completethepassagebelowwiththecorrectformofwordsinthebox.shade,artist,painter,painting,exhibition,gallery,detail,emphasise,elegantIhadthemostinterestingafternoonyesterday.Imetan(1)_____andsheshowedmesomeofherpaintingsinanart(2)______.Shealsotoldmeabouthowshestartedtodrawataveryartistgallery3Completethepassagebelowwit20youngageanddecidedtobea(3)_____whenshewasten!Thisisherfirst(4)_________anditisgoingreallywell.Sofar,shehassoldsix(5)_________!Ireallyloveherworkbecauseherpaintingsarefilledwith(6)________.Shealwayspaints(7)_______womeningardens.painterpaintingselegantexhibitioneleganceyoungageanddecidedtobea21IwishIcouldhaveboughtapainting,buttheyaretooexpensiveforme!color(9)__________thewomen’sbeauty.emphasisesHeruseofmanydifferent(8)_______ofshadesIwishIcouldhaveboughtap22Whoisfamousfordrawingprettywomen?Whoisbetteratdrawingsimplepicturesweoftenseeinourlife.ChenYifei.Heisfamousforhissoftportraitsofbeautifulwomen.Hedrawssimplepicturesfromeverydaylife,suchasvegetables,flowers,birdsandinsects.QiBaishiWhoisfamousfordrawingpre234.WhoheldexhibitionsabroadtoadvanceChineseart?5.WhatisXuBeihong’smasterpiece?XuBeihong.Racinghorse.3.WhydidChenYifeiuseblackasthebackgroundofPoppy?Toemphasisethewomanevenmore.4.Whoheldexhibitionsabroad24CorrectionChenYifei’sworksareveryvaluable,andoneofhispaintingssoldatUS$503,000.Theendofthenovelleavesreadersguessandimagining.Herhandholdthefaniselegantlypositionedaboveherknees.forguessingholdingCorrectionChenYifei’sworksa254.Hetraveledcrossthecountryandpaintedmanypictures.5.Itsbackeyes,thatarefixedonthecabbage,showthecreature’sinterestinthecabbage.6.Thepaintingofdarkandlightcolorsisfavoriteofmanyartlovers.acrosswhicha∧4.Hetraveledcrossthecountr26Languagepoints1.befixedon用（眼睛等）盯住，凝视；吸引（注意）他盯着这条蠕动的蛇，充满了恐惧。Hewasfixedonthemovingsnake,fulloffear.汤姆的注意力都集中在他正在画的图上。Tomfixedhisattentiononthepicturethathewasdrawing.Languagepoints1.befixedon272.leave

表示“使/让（某人/某物）处于某状态。后面接现在分词(V-ing)、形容词、过去分词(V-ed)作宾语补足语。别让她在外边雨中等着。Don’tleaveherwaitingoutsideintherain.让门开着吧。Leavethedooropen,please.小汤姆跑了出去，留下了没写完的作业。LittleTomranoutofthedoor,leavingthehomeworkundone.2.leave表示“使/让（某人/某物）处于某状态。后面283.bedeep/lostinthought陷入沉思迪克盯着窗外，陷入了沉思。Dickwasstaringoutofthewindow,lostinthought.4.add…to

增添，添加你想把自己的名字加到名单里吗？Doyouwanttoaddyourname

tothelist?3.bedeep/lostinthought陷入29Practiceforvocabulary

Completethesentenceswiththewordsbelow.add,audience,combine,creative,critic,emphasise,fix,imagination,promote,traditionPracticeforvocabularyComple301.Hedesignedthefirstgreatsuspensionbridge,anideathat________beautyandfunctionperfectly.2.John_____somewatertothepainttomakeitthinner.3.She_____hereyesonthejaggedlineofrockstowhichshehadtoclimb.4.Youdon’thavetouseyour__________whenyou’rewatchingtelevision.5.Abalanceddiet________binesaddedfixedimaginationpromotes1.Hedesignedthefirstgreat316.Theshowhasdelightedtelevision________intheUnitedStatesandBritain.7.ThePrimeMinister__________thattherearenoplanstoraisetaxes.

8.WealwaysgoforalongwalkonChristmasmorning.It’safamily________.9.Ididn’tthinkthebookwasasbadasthe______saiditwas.

10.Ienjoymyjob,butI’dliketodosomethingmore________.audienceemphasisedtraditioncriticscreative6.Theshowhasdelightedtele32翻译句子1一条铁路上有许多固定了的枕木。Manysleeperswerefixedonarailway.

2这个老人凝神沉思，没有听见我们进来。Theoldmanwaslostinthoughtanddidnothearuscomein.

3四加五等于九。Ifyouadd4to5,youget9.

翻译句子1一条铁路上有许多固定了的枕木。33GrammarPrepositionsoftime,place,andmovementAprepositiondescribesarelationshipbetweenotherwordsinasentence.GrammarPrepositionsoftime,p34介词是一种用来表示词与词,词与句之间的关系的词。在句中不能单独作句子成分。介词后面一般有名词、代词或相当于名词的其他词类，短语或从句作它的宾语。介词和它的宾语构成介词词组，在句中作定语,状语，表语，补语等。介词是一种用来表示词与词,词与句之间的关系的词。在句中不能35Whichprepositionsareexpressionsoftimeexpressionsofplaceexpressionsofmovementnearthecabbageaboveherkneesbehindthewomanduringhislifetimebetween1933and1940acrossthispaintingalongthehorse’sbodyWhichprepositionsareexpressi36表示时间的介词，at,on,in,during,for,to,till,until,after,by,before等。表示时间的介词，at,on,in,during,fo371.at,on,inat用来表示时间时，通常指时间的某一点。如：atfiveo’clock,atnoon,atmidnighton用来表示某一段时间，特指某天或某天的上午,下午或晚上。如：onSunday,onOctober,onSaturdaymorning.in也可用来表示一段时间，但多指长于一天或不到一天的时间段。如：inJanuary,insummer,in1988,inthemorning,intheevening.1.at,on,in382.in与duringduring用来表示一段时间，其意义大致相当于in的用法。一般来说，凡是能用in的地方，也可以用during.如：Hecametoseemeduringmyabsence.Don’tgotoseehiswifeinhisabsence.during与in的区别在于during强调时间的延续性，而in则只是一般指某一时间。试比较：TheyvisitedmanycitiesduringtheirstayinChina.Hergrandpawaskilledinthewar.2.in与during393.in,for,during“in＋时间”与“for＋时间”都可表示一段时间，但“for＋时间”表示“有多久”，而“in＋时间”则表示“在何时”。如：Weworkedthereforthewinter.Theyworkedthereinwinter.以上两例中，inwinter强调“在冬季”，不一定包括整个冬季时间，而forthewinter则强调“整个冬天”。for用来表示一般时间，常跟具体的时间段。如forafewdays，for3weeks，forfivemonths等。3.in,for,during404.since与after都可以用来引导表示从过去某一点开始的时间段词组。它们的不同之处在于：since引导的词组所表示的时间一直延续到说话时为止，因而要与现在完成时连用。如：Hehasbeentheretwicesince1982.Ihavedonenothingsincesixo’clock.after引导的词组所表示的时间纯系过去，并不延续到说话时，因此要和一般过去时连用。如：Hewenthomeafterschool.4.since与after都可以用来引导表示从过去某一点开415.till,until与to介词till／until常用于“from.……till／until”结构中，表示“一个动作的终结”。介词to常用在“from.……to”的结构中，用来表示“一个阶段的终结”。两者在这种结构中意义十分接近。如：TheAmericansstayedherefromJunetoSeptember.Hestudiesfrommorningtill／untilnighteveryday.5.till,until与to42to可用在表示钟点的词前。我们说It’ssixtofive但不能说It’ssixtill／untilfive.反之在某些能用till／until的场合，却不能用to.如：在“not.……until”结构中，我们说Ididn’tgotobedtill／untilteno’clock.却不能说Ididn’tgotobedtoteno’clock.

till与until也有细微区别。till常用在非正式文体或口语中，而until则常用于正式文体及比较正式的场合。另外，在句首多用until.to可用在表示钟点的词前。我们说It’ssixt436.by,beforeby表示时间时，意思是“到……以前”、“不迟于”、“到……时（为止）”。例如：bysuppertime,bytheendoflasttermbefore表示时间，意为“在……以前”。例如：beforeliberation,thedaybeforeyesterday6.by,before44c）by与before的区别在于，by短语表示时间，强调“终止点”，而before短语表示时间，强调“起始点”。如：Yoursonwillbeallrightbysuppertime.句中的bysuppertime表示从说话时到晚饭前这段时间。而before构成短语则表示从某一时间或事件之前，如：Thepoorchildrencouldn’tgotoschoolbeforeliberation.c）by与before的区别在于，by短语表示时间，强调“终45表示地点的介词above

thelake/belowtheclouds,athome,atthebank,attheseaside,behindthetree,betweenthebankandthepark,inBakerStreet,inthebox,inthepicture,onthetable,onthebus,onthefirstfloor,underthebridge/overthetable表示地点的介词abovethelake/belowt46表示动作的介词acrossthepark,alongtheriver,intothebuilding,to/fromWarsaw表示动作的介词acrossthepark,along47Answersforreferenceexpressionsoftimeexpressionsofplaceexpressionsofmovementduringbetweenbehindnearbetweenaboveacrossalong4Answersforreferenceexpressio48Completethisdescriptionofthepicturewiththecorrectprepositions.6Completethisdescriptionoft49Thiswasprobablypainted(1)___(in/at)thenineteenthcenturyandshowspeople(2)___(in/between)apark,

(3)___(in/on)aSundayafternoon.Somepeoplearesitting(4)___(on/in)thegrass(5)_____(under/on)thetreesandothersarejustwalking(6)___(in/to)thepark.ononunderinininThiswasprobablypainted(1)50(7)____(In/On)thebackground,(8)___(on/in)theleft,thereareafewboats(9)___(above/on)thelake.Somepeoplearestanding(10)_____(across/near)thewaterlookingattheboats.(11)____(In/On)thecentreofthepicturethereisawomanandagirl.Thewomanisholdinganumbrella(12)_____(above/on)herhead.ononInnearInabove(7)____(In/On)thebackgroun51(13)___(In/On)theforeground,(14)___(in/on)theleft,awomanissitting(15)_______(between/above)twomen.Ablackdogisstanding(16)______(during/behind)them.onbetweenbehindIn(13)___(In/On)theforegroun52翻译句子1.他夏天每天游泳。Heswimseverydayduringthesummer.2.那个醉汉摇摇晃晃地穿过房间。Thedrunkmanstaggeredacrosstheroom.

3.他年近四十。Heisnearforty.

4.他是幕后策划人。Heisbehindtheplan.

翻译句子1.他夏天每天游泳。53HomeworkDescribeapictureoraphotowiththewordswehavelearnedtoday.HomeworkDescribeapictureor54Lesson1Lesson155Lookatthepictures,whichdoyoulikebest?Why?BeforeyoustartLookatthepictures,whichdo56北师大版高一英语必修二课件：unit6-Design-Lesson-157WordsPreviewexhibitionpoetrymissilemaneshadesweatyouthn.展览会n.诗（总称）n.导弹n.鬃毛n.阴影，阴暗处n.汗n.青春，年轻人WordsPreviewexhibitionn.展览会58insectfixone’seyesoncreatureartistvaluabletypicalelegantlyWordsPreviewn.昆虫注视，凝视n.动物，人n.艺术家，画家adj.贵重的，有价值的adj.典型的adv.优美地insectWordsPreviewn.昆虫59emphasisedetailclothfoldshallowshoreeyesightWordsPreviewvt.强调n.细节，详情n.布，布料n.褶皱adj.浅的n.岸边n.视力emphasiseWordsPreviewvt.强调60Learnsomethingmoreaboutthepaintersoftheseworks,getmoreinformationofthesegreatartists.Learnsomethingmoreaboutthe61北师大版高一英语必修二课件：unit6-Design-Lesson-162齐白石（1864－1957），湖南湘潭人，二十世纪中国画艺术大师，二十世纪十大书法家,画家之一，世界文化名人。齐白石（1864－1957），湖南湘潭人，二十世纪中国画艺术63北师大版高一英语必修二课件：unit6-Design-Lesson-164北师大版高一英语必修二课件：unit6-Design-Lesson-165徐悲鸿(1895-1953),是兼采中西艺术之长的现代绘画大师,前驱式的美术教育家。徐悲鸿(1895-1953),是兼采中西艺术之长的现代绘画大66北师大版高一英语必修二课件：unit6-Design-Lesson-167北师大版高一英语必修二课件：unit6-Design-Lesson-168陈逸飞(1946-2005)生于宁波，浙江镇海人。1984年，美国《艺术新闻》杂志将陈逸飞定名为“一个浪漫的写实主义者，作品流露强烈的怀旧气息，弥漫其中的沉静与静寂氛围尤其动人。”陈逸飞(1946-2005)生于宁波，浙江镇海人。198469北师大版高一英语必修二课件：unit6-Design-Lesson-170Readthetextsandcompletethenotes.PlaceDatesArtistsPaintingsNewmanGallery,Dinham1Julyto15SeptemberXuBeihong,QiBaishiandChenYifeiRacingHorse,CabbageandPoppy2Readthetextsandcompleteth71SubjectsofpaintingsColoursusedahorserunningathighspeed;atinyinsectfixingitseyesonthecabbagenearby;

ayoungwomansittingalone,deepinthought,herhandholdingthefanaboveherknees

black,grey,dark,lightSubjectsofpaintingsColoursu72ReadingExhibition:ChinesePrintsXuBeihongQiBaishiChenYifeiRacingHorseCabbagePoppyReadingExhibition:ChinesePri73Completethepassagebelowwiththecorrectformofwordsinthebox.shade,artist,painter,painting,exhibition,gallery,detail,emphasise,elegantIhadthemostinterestingafternoonyesterday.Imetan(1)_____andsheshowedmesomeofherpaintingsinanart(2)______.Shealsotoldmeabouthowshestartedtodrawataveryartistgallery3Completethepassagebelowwit74youngageanddecidedtobea(3)_____whenshewasten!Thisisherfirst(4)_________anditisgoingreallywell.Sofar,shehassoldsix(5)_________!Ireallyloveherworkbecauseherpaintingsarefilledwith(6)________.Shealwayspaints(7)_______womeningardens.painterpaintingselegantexhibitioneleganceyoungageanddecidedtobea75IwishIcouldhaveboughtapainting,buttheyaretooexpensiveforme!color(9)__________thewomen’sbeauty.emphasisesHeruseofmanydifferent(8)_______ofshadesIwishIcouldhaveboughtap76Whoisfamousfordrawingprettywomen?Whoisbetteratdrawingsimplepicturesweoftenseeinourlife.ChenYifei.Heisfamousforhissoftportraitsofbeautifulwomen.Hedrawssimplepicturesfromeverydaylife,suchasvegetables,flowers,birdsandinsects.QiBaishiWhoisfamousfordrawingpre774.WhoheldexhibitionsabroadtoadvanceChineseart?5.WhatisXuBeihong’smasterpiece?XuBeihong.Racinghorse.3.WhydidChenYifeiuseblackasthebackgroundofPoppy?Toemphasisethewomanevenmore.4.Whoheldexhibitionsabroad78CorrectionChenYifei’sworksareveryvaluable,andoneofhispaintingssoldatUS$503,000.Theendofthenovelleavesreadersguessandimagining.Herhandholdthefaniselegantlypositionedaboveherknees.forguessingholdingCorrectionChenYifei’sworksa794.Hetraveledcrossthecountryandpaintedmanypictures.5.Itsbackeyes,thatarefixedonthecabbage,showthecreature’sinterestinthecabbage.6.Thepaintingofdarkandlightcolorsisfavoriteofmanyartlovers.acrosswhicha∧4.Hetraveledcrossthecountr80Languagepoints1.befixedon用（眼睛等）盯住，凝视；吸引（注意）他盯着这条蠕动的蛇，充满了恐惧。Hewasfixedonthemovingsnake,fulloffear.汤姆的注意力都集中在他正在画的图上。Tomfixedhisattentiononthepicturethathewasdrawing.Languagepoints1.befixedon812.leave

表示“使/让（某人/某物）处于某状态。后面接现在分词(V-ing)、形容词、过去分词(V-ed)作宾语补足语。别让她在外边雨中等着。Don’tleaveherwaitingoutsideintherain.让门开着吧。Leavethedooropen,please.小汤姆跑了出去，留下了没写完的作业。LittleTomranoutofthedoor,leavingthehomeworkundone.2.leave表示“使/让（某人/某物）处于某状态。后面823.bedeep/lostinthought陷入沉思迪克盯着窗外，陷入了沉思。Dickwasstaringoutofthewindow,lostinthought.4.add…to

增添，添加你想把自己的名字加到名单里吗？Doyouwanttoaddyourname

tothelist?3.bedeep/lostinthought陷入83Practiceforvocabulary

Completethesentenceswiththewordsbelow.add,audience,combine,creative,critic,emphasise,fix,imagination,promote,traditionPracticeforvocabularyComple841.Hedesignedthefirstgreatsuspensionbridge,anideathat________beautyandfunctionperfectly.2.John_____somewatertothepainttomakeitthinner.3.She_____hereyesonthejaggedlineofrockstowhichshehadtoclimb.4.Youdon’thavetouseyour__________whenyou’rewatchingtelevision.5.Abalanceddiet________binesaddedfixedimaginationpromotes1.Hedesignedthefirstgreat856.Theshowhasdelightedtelevision________intheUnitedStatesandBritain.7.ThePrimeMinister__________thattherearenoplanstoraisetaxes.

8.WealwaysgoforalongwalkonChristmasmorning.It’safamily________.9.Ididn’tthinkthebookwasasbadasthe______saiditwas.

10.Ienjoymyjob,butI’dliketodosomethingmore________.audienceemphasisedtraditioncriticscreative6.Theshowhasdelightedtele86翻译句子1一条铁路上有许多固定了的枕木。Manysleeperswerefixedonarailway.

2这个老人凝神沉思，没有听见我们进来。Theoldmanwaslostinthoughtanddidnothearuscomein.

3四加五等于九。Ifyouadd4to5,youget9.

翻译句子1一条铁路上有许多固定了的枕木。87GrammarPrepositionsoftime,place,andmovementAprepositiondescribesarelationshipbetweenotherwordsinasentence.GrammarPrepositionsoftime,p88介词是一种用来表示词与词,词与句之间的关系的词。在句中不能单独作句子成分。介词后面一般有名词、代词或相当于名词的其他词类，短语或从句作它的宾语。介词和它的宾语构成介词词组，在句中作定语,状语，表语，补语等。介词是一种用来表示词与词,词与句之间的关系的词。在句中不能89Whichprepositionsareexpressionsoftimeexpressionsofplaceexpressionsofmovementnearthecabbageaboveherkneesbehindthewomanduringhislifetimebetween1933and1940acrossthispaintingalongthehorse’sbodyWhichprepositionsareexpressi90表示时间的介词，at,on,in,during,for,to,till,until,after,by,before等。表示时间的介词，at,on,in,during,fo911.at,on,inat用来表示时间时，通常指时间的某一点。如：atfiveo’clock,atnoon,atmidnighton用来表示某一段时间，特指某天或某天的上午,下午或晚上。如：onSunday,onOctober,onSaturdaymorning.in也可用来表示一段时间，但多指长于一天或不到一天的时间段。如：inJanuary,insummer,in1988,inthemorning,intheevening.1.at,on,in922.in与duringduring用来表示一段时间，其意义大致相当于in的用法。一般来说，凡是能用in的地方，也可以用during.如：Hecametoseemeduringmyabsence.Don’tgotoseehiswifeinhisabsence.during与in的区别在于during强调时间的延续性，而in则只是一般指某一时间。试比较：TheyvisitedmanycitiesduringtheirstayinChina.Hergrandpawaskilledinthewar.2.in与during933.in,for,during“in＋时间”与“for＋时间”都可表示一段时间，但“for＋时间”表示“有多久”，而“in＋时间”则表示“在何时”。如：Weworkedthereforthewinter.Theyworkedthereinwinter.以上两例中，inwinter强调“在冬季”，不一定包括整个冬季时间，而forthewinter则强调“整个冬天”。for用来表示一般时间，常跟具体的时间段。如forafewdays，for3weeks，forfivemonths等。3.in,for,during944.since与after都可以用来引导表示从过去某一点开始的时间段词组。它们的不同之处在于：since引导的词组所表示的时间一直延续到说话时为止，因而要与现在完成时连用。如：Hehasbeentheretwicesince1982.Ihavedonenothingsincesixo’clock.after引导的词组所表示的时间纯系过去，并不延续到说话时，因此要和一般过去时连用。如：Hewenthomeafterschool.4.since与after都可以用来引导表示从过去某一点开955.till,until与to介词till／until常用于“from.……till／until”结构中，表示“一个动作的终结”。介词to常用在“from.……to”的结构中，用来表示“一个阶段的终结”。两者在这种结构中意义十分接近。如：TheAmericansstayedherefromJunetoSeptember.Hestudiesfrommorningtill／untilnighteveryday.5.till,until与to96to可用在表示钟点的词前。我们说It’ssixtofive但不能说It’ssixtill／untilfive.反之在某些能用till／until的场合，却不能用to.如：在“not.……until”结构中，我们说Ididn’tgotobedtill／untilteno’clock.却不能说Ididn’tgotobedtoteno’clock.

till与until也有细微区别。till常用在非正式文体或口语中，而until则常用于正式文体及比较正式的场合。另外，在句首多用until.to可用在表示钟点的词前。我们说It’ssixt976.by,beforeby表示时间时，意思是“到……以前”、“不迟于”、“到……时（为止）”。例如：bysuppertime,bytheendoflasttermbefore表示时间，意为“在……以前”。例如：beforeliberation,thedaybeforeyesterday6.by,before98c）by与before的区别在于，by短语表示时间，强调“终止点”，而before短语表示时间，强调“起始点”。如：Yoursonwillbeallrightbysuppertime.句中的bysuppertime表示从说话时到晚饭前这段时间。而b