国家开放大学《理工英语3》教学辅导3段落的写作

经典word整理文档，仅参考，双击此处可删除页眉页脚。本资料属于网络整理，如有侵权，请联系删除，谢谢！英语作文段落的写作段落发展的手段基本句法掌握之后，接下来就要训练段落写作，这是因为段落是文章的基本组成部分，要写出好文章，必须在段落写作上多下功夫。段的基本组成是句子，好的段落应该是该段中所有的句子都围绕着一个主题展开，且句与句之间应该是紧密相连，形成统一的整体即unifiedandcoherent。那么怎样将一个段落展开呢？下面介绍英语中几种常用的方法。1．叙述法(narration)叙述法发展段落主要是按照事物本身的时间或空间的排列顺序，通过对一些特有过渡连接词的使用，有层次分步骤地表达主题句的一种写作手段。用这种方法展开段落，能够清楚连贯地交待事物的本末，从而可以使读者可以清晰、完整地理解文章的含义，例如：Intheflatopposite,awomanheardthenoiseoutside.Whenshelookedoutthroughthewindow,shediscoveredthatherneighborwasthreatenedbysomeone.Sheimmediatelycalledthepolicestation.Inanswertothecall,apatrolpolicecararrivedatthesceneofthecrimequickly.Threepolicemenwentinsidetheflatatonce,andothersguardedoutsidethebuildingtopreventanyonefromescaping.这段是按照事物发展的先后顺序，叙述从发现案情、报警、到警察赶到、包围现场的过程。全文脉络清晰，叙述的层次感强，结构紧凑。常用于叙述法中的过渡连接词有：first,atthebeginning,tostartwith,afterthat,later,then,afterwards,intheend,finally等。2.举例法(example)通过举出具体事例来阐述、说明主题句的内容，严格地讲，举例法也是列举法的一种，它们的区别在于：列举法侧重罗列事实，所列事实力求全面；而举例法侧重通过举出典型事例来解释观点，且事例可多可少。我们来看下面这个用举例法展开的段落。Therearemanydifferentformsofexercisestosuitdifferenttastes.Forexample,thosewhoenjoycompetitivesportsmaytakeupballgames.Foranotherexample,iftheyprefertoexercisealone,theycanhavearunortakeawalkinthemorningorintheevening.Besides,peoplecangoswimminginthesummerandgoskatinginthewinter.Inshort,nomatterwhattheirinterestsare,peoplecanalwaysfindmorethanonesportsthataresuitabletothem.本段采用了三个事例来说明主题句中的关键词组differentformsofexercises，这三个例子分别由连接词forexample,foranotherexample和besides全段内容。举例法中常用的连接词有：forexample(instance),oneexampleis,besides,furthermore,moreover,inaddition等。3．列举法(details)运用列举法，是通过列举一系列的论据对topicsentence中摆出的论点进行广泛、全面地陈述或解释，列举的顺序可以按照所列各点内容的相对重要性、时间、空间等进行。YesterdaywasoneofthoseawfuldaysformewheneverythingIdidwentwrong.First,Ididn'thearmyalarmclockandarrivedlateforwork.Then,Ididn'treadmydiaryproperlyandforgottogettoanimportantmeetingwithmyboss.Duringthecoffeebreak,Idroppedmycoffeecupandspoiltmynewskirt.Atlunchtime,Ileftmypurseonabusandlostallthemoneythatwasinit.Afterlunch,mybosswasangrybecauseIhadn'tgonetothemeeting.ThenIdidn't1noticeasignonadoorthatsaid"WetPaint"andsoIspoiltmyjackettoo.WhenIgothomeIcouldn'tgetintomyflatbecauseIhadleftmykeyinmyoffice.SoIbrokeawindowtogetinandcutmyhand.根据本段主题句中的关键词组everythingIdidwentwrong，列举了8点内容，分别由first,then,duringthecoffeebreak,afterlunchtime络分明、内容连贯。常用于列举法的过渡连接词有：foronething,foranother,finally,besides,moreover,oneanother,stillanother,first,second,also等。4．对比法或比较法(comparison&contrast)将同类的事物按照某种特定的规则进行比较分析是一种常用的思维方法。通过对比，更容易阐述所述对象之间的异同和优缺点，例如：Theheartofanelectroniccomputerliesinitsvacuumtubes,ortransistors.Itselectroniccircuitsworkathousandtimesfasterthanthenicercellsinthehumanbrain.Aproblemthatmighttakeahumanbeingalongtimetosolvecanbesolvedbyacomputerinoneminute.在这段文字上，为了突出电子计算机运行速度之快，首先将它与人脑进行了比较，"--athousandtimesfasterthan--";而后，又将这一概念具体到了"aproblem"上，通过对比使读者从"--alongtime--inoneminute"上有更加直观的认识。常用于对本法或比较法上的过渡连接词有：then,comparedwith等。5．分类法(classification)在阐述某一概念的段落中，常用分类法。通过对概念中所包括的事物进行分门别类，分别加以叙述，使读者有更为清晰的认识，如：Eversincehumanshavelivedontheearth,theyhavemadeuseofvariousformsofcommunication.Generally,thisexpressionofthoughtsandfeelingshasbeenintheformoforalspeech.Whenthereisalanguagebarrier,communicationisaccomplishedthroughsignlanguageinwhichmotionsstandforletters,wordsandideas.Touristsandthepeopleunabletohearorspeakhavehadtoresorttothisformofexpression.Manyofthesesymbolsofwholewordsareveryvividandexactandcanbeusedinternationally;spelling,however,cannot.Bodylanguagetransmitsideasorthoughtsbycertainactions,eitherintentionallyorunintentionally.Anodsignifiesapproval,whileshakingtheheadindicatesanegativereaction.Otherformsofnonlinguisticlanguagecanbefoundinsignalflags,Morsecode,andpicturesigns.在该段中为了说明topicsentence中的"variousformsofcommunication"，将其分为oralspeech,signlanguage,bodylanguage及otherformsofnonlinguisticlanguage采用这种方法的段落并没有标志突出的连接词，所述各项均为平行并列关系，所以没有明显的主次之分。6．因果分析法(causeandeffect)在阐述某一现象的段落中，常采用因果分析法。例如：Theroleofwomenintoday'ssocietyischanging.Onereasonisthatwomenhavebeguntoassertthemselvesasindependentpeoplethroughthewomen'smovement.Also,womenareawareofthealternativestostayingathome.Anotherreasonisthatincreasingnumbersofwomenwhoenternewfieldsandinterestsserveasrolemodelsforotherwomen.Moreover,menarebecomingmoreconsciousoftheabilitiesofwomenandhavebeguntoviewtheirindependencepositively.本段中，主题句提出了一种社会现象，推展句则对产生这种现象的原因作出各种解释。常用于因果分析法的连接词有：because,so,asaresult等。7．定义法(definition)2在科普文章的写作中，定义法是必不可少的。通过下定义，可以使读者对该事物有一个更直接的认识。Automationreferstotheintroductionofelectroniccontrolandautomationoperationofproductivemachinery.Itreducesthehumanfactors,mentalandphysical,inproduction,andisdesignedtomakepossiblethemanufactureofmoregoodswithfewerworkers.ThedevelopmentofautomationinAmericanindustryhasbeencalledthe"SecondIndustrialRevolution".这一段文字使我们了解了"automation"和"SecondIndustrialRevolution"别由"refersto"和"beencalled"引出。常出现在定义法中的词语有：referto,mean,call等。8．重复法(repetition)句子的一部分反复出现在段落中，这就是重复法。它往往造成一种步步紧逼的气氛，使文章结构紧凑，有感染力。比如：Sincethattime,whichisfarenoughawayfromnow,Ihaveoftenthoughtthatfewpeopleknowwhatsecrecythereisintheyoung,underterror.Iwasinmortalterroroftheyoungmanwhowantedmyheartandliver;Iwasinmortalterrorofmyinterlocutorwiththeironleg;Iwasinmortalterrorofmyself,fromwhomanawfulpromisehadbeenextracted;--该段中反复应用了Iwasinmortalterrorof…我经常处于恐怖之中。以上，我们结合具体文章讨论了展开段落的几种方法。在实际写作中，我们往往不必拘泥于一种写作方法，而是将若干方法穿插在一起，使文章有声有色。段落写作的三个标准整个段落必须紧扣这个主题(stickorholdtothetopic)，这就是段落的统一性(unity)。其次，一个段落必须有若干拓展句，使主题思想得到充分展开，从而给读者一个完整的感觉，这就是完整性(completenessoradequateness)句子的排列顺序必须合乎逻辑，从一个句子到另一个句子的过渡必须流畅(smooth)，这就是连贯性(coherence)。下面我们就对这三个标准分别加以说明。1．统一性一个段落内的各个句子必须从属于一个中心，任何游离于中心思想之外的句子都是不可取的。请看下例：JoeandIdecidedtotakethelongtripwe'dalwayswantedacrossthecountry.Wewerelikeyoungkidsbuyingourcamperandstockingitwithallthenecessitiesoflife.Bellabakesthebestrhubarbpie.WestartedoutinearlyspringfromMinneapolisandheadedwestacrossthenorthernpartofthecountry.Webothenjoyedthosepeoplewemetatthetrailerpark.Joereceivedawatchathisretirementdinner.Tooursurprise,wefoundthatwelikedthewarmsouthernregionsverymuch,andsowedecidedtostayhereinNewMexico.本段的主题句是段首句，controllingidea（中心思想）是takethelongtripacrossthecountry。文中出现两个irrelevantsentences，一个是Bellabakesthebestrhubarbpie，这一段是讲的是JoeandI，中间出现一个Bella是不合适的。还有，Joereceivedawatchathisretirementdinner这一句更是与主题句不相关。考生在作文上常常因为造出irrelevantsentences（不相关语句）而丢分，值得引起注意。再看一个例子：MynameisRoseanna,andIliketokeepphysicallyfit.Iusedtoweightwohundredpounds,butIjoinedtheYMCAforanexerciseclassanddietprogram.InoneyearIlosteightypounds.Ifeelmuchbetterandneverwanttohavethatmuchweightonmyfive-feetframeagain.Iboughttwonewsuitcaseslastweek.EverydayIpracticejoggingthreemiles,swimmingfifteenlaps,3liftingtwenty-poundweightsandplayingtennisforonehour.Mymotherwasaprematurebaby.本段的controllingidea是liketodeepphysicallyfit，但段中有两个irrelevantsentences，一个是Iboughttwonewsuitcaseslastweek，另一个是Mymotherwasaprematurebaby。从上面两个例子可以看出，nativespeakers同样会造出来irrelevantsentences。卷面上如果这种句子多了，造成偏题或离题，那问题就更严重了。2．完整性正象我们前面说得那样，一个段落的主题思想靠推展句来实现，如果只有主题句而没有推展句来进一步交待和充实，就不能构成一个完整的段落。同样，虽然有推展句，但主题思想没有得到相对圆满的交待，给读者一种意犹未尽的感觉。这样的段落也不能完成其交际功能。例如：Physicalworkcanbeausefulformoftherapyforamindinturmoil.Workconcentratesyourthoughtsonaconcretetask.Besides,itismoreusefultowork----youproducesomethingratherthanmoreanxietyordepression.“amindinturmoil”（心境不平静）Physicalwork又如何能改变这种情况？为什么它能起therapy的作用？读者得不到明确的答案。由于一般作文写作只要求写一篇120或200个词的三段式短文，每一段词数既有限制，因此，要达到完整就必须尽可能地简明。例如：Itisnotalwaystruethatagoodpictureisworthathousandwords.Oftenwritingismuchclearerthanapicture.Itissometimesdifficulttofigureoutwhatapicturemeans,butacarefulwritercanalmostalwaysexplainit.段首句所表达的主题思想是一种看法，必须有具体事例加以验证。上述两个推展句只是在文字上对主题作些解释，整个段落内容空洞，简而不明。如果用一两个具体的例子的话，就可以把主题解释清楚了。比如下段：Itisnotalwaystruethatapictureisworthathousandwords.Sometimes,picturesareprettyuselessthings.Ifyoucan’tswimandfallintheriverandstartgulpingwater,willyoubebetterofftoholdupapictureofyourselfdrowning,orstartscreaming"Help"?3．连贯性当然这两者常常是不可分割的。只有形连而没有意连，句子之间就没有内在的有机的联系；反之，只有意连而没有形连，有时行文就不够流畅。1)意连段落中句子的排列应遵循一定的次序，不能想到什么就写什么。如果在下笔之前没有构思，边写边想，写写停停，那就写不出一气呵成的好文章来。一可以按照时间先后(chronologicalarrangement)，位置远近(spatialarrangement)（当然，按位置远近来写不等于都是由远及(logicalarrangement)，重要性顺序(arrangementinorderofimportance)，由一般到特殊（general-to-specificarrangement(specific-to-generalarrangement)等的排列方式来排列。下面是由一般到特殊general-to-specificarrangement）以及由特殊到一般(specific-to-generalarrangement)的两个例子：a)由一般到特殊(general-to-specificarrangement）Ifareaderislost,itisgenerallybecausethewriterhasnotbeencarefulenoughtokeephimonthepath.Thiscarelessnesscantakeanynumberofforms.Perhapsasentenceissoexcessivelyclutteredthatthereader,hackinghiswaythroughtheverbiage,simplydoesn'tknowwhatitmeans.4Perhapsasentencehasbeensoshoddilyconstructedthatthereadercouldreaditinanyofseveralways.Perhapsthewriterhasswitchedtenses,orhasswitchedpronounsinmid-sentence,sothereaderlosestrackofwhentheactiontookplaceorwhoistalking.PerhapssentenceBisnotlogicalsequeltosentenceA----thewriter,inwhoseheadtheconnectionisclear,hasnotbotheredtoprovidethemissinglink.Perhapsthewriterhasusedanimportantwordincorrectlybynottakingthetroubletolookitup.Hemaythinkthat"sanguine"and"sanguinary"meanthesamething,butthedifferenceisabloodybigone.Thereadercanonlyinferwhatthewriteristryingtoimply.这一段谈的是awriter'scarelessness，先给出一个generalstatement作为主题句，然后通过5个＂perhaps＂加以例证。b)由特殊到一般(specific-to-generalarrangement)IdonotunderstandwhypeopleconfusemySiamesecat,Prissy,withtheoneIhadseveralyearsago,Henry.Thetwocatsareonlyalikeinbreed.Prissy,aquiet,femininefeline,lovesmedearlybutnotpossessively.Shelikestokeepherdistancefrompeople,exertherindependenceandisneversorudeastobeg,lick,orsniffunceremoniously.Herusualpostureissittingupright,eyesclosed,perfectlystill.Prissyisaverypropercat.Henry,ontheotherhand,lovedmedearlybutpossessively.Hewasmyshadowfrommorningtillnight.Heexpectedmetoconstantlyentertainhim.Henrynevercaredwhosawhimdoanything,whetheritwasdecorousornot,andheusuallyoffendedmyfriendsinsomeway.Thecatmadehimselfquitecomfortable,onthetopofthetelevision,acrossstranger'sfeetorlaps,inbeds,drawers,sacks,closets,ornooks.Thedifferencebetweenthemisimperceptibletostrangers.本段的主题句是段首句，它仅提出一个问题：为什么两只猫会被搞混。然后对两者进行比较，末句才下结论。2）形连行文的逻辑性常常要靠适当的转换词语及其他手段来实现。请读下面这一段文字并找出文中用以承上启下的词语：Walter'sgoalinlifewastobecomeasuccessfulsurgeon.First,though,hehadtogetthroughhighschool,soheconcentratedallhiseffortsonhisstudies---inparticular,biology,chemistry,andmath.Becauseheworkedconstantlyonthesesubjects,Walterbecameproficientinthem;however,Walterforgotthatheneededtomasterothersubjectsbesidesthosehehadchosen.Asaresult,duringhisjunioryearofhighschool,WalterfailedbothEnglishandLatin.Consequently,hehadtorepeatthesesubjectsandhewasalmostunabletograduateonschedule.Finally,onJune6,Walterachievedthefirststeptowardrealizinghisgoal.本文中起承上启下的词语有两种，一种是转换词语(transitionalwordsorphrases)，另一种是起转换作用的其他连接手段(linkingdevices)first,though,so,inparticular,and,because,however,besides,asaresult,both…and,consequently,and,finally.后者依次是：he,he,his,his,he,these,them,he,those,his,he,these,his.本段中共有词汇105个，所使用的转换词语及其他连接用语共26个词，约占该段总词汇量的四分之一。由此可见，掌握好transitions不仅对行文的流畅(smoothness)有益，而且对于学生在规定时间内写足短文所要求的词量也是不无好处的。一个段落里如果没有transitions也就很难有coherence了。我们看下面一个例子：Speakingandwritingaredifferentinmanyways.Speechdependsonsounds.Writinguseswrittensymbols.Speechdevelopedabout500000yearsago.Writtenlanguageisarecentdevelopment.Itwasinventedonlyaboutsixthousandyearsago.Speechis5usuallyinformal.Thewordchoiceofwritingisoftenrelativelyformal.Pronunciationandaccentoftentellwherethespeakerisfrom.Pronunciationandaccentareignoredinwriting.Astandarddictionandspellingsystemprevailsinthewrittenlanguageofmostcountries.Speechreliesongesture,loudness,andriseandfallofthevoice.Writinglacksgesture,loudnessandtheriseandfallofthevoice.Carefulspeakersandwritersareawareofthedifferences.本段中除了第6句开头出现一个起过渡作用的＂it＂之外，没有使用其他的过渡词语.这样，文中出现许多重复的词语，全段读起来也显得生硬而不自然。如果加上必要的过渡词语来修饰的话，这一段就成了下面一个流畅连贯的段落：Speakingandwritingaredifferentinmanyways.Speechdependsonsounds;writing,ontheotherhand,useswrittensymbols.Speechwasdevelopedabout500000yearsago,butwrittenlanguageisarecentdevelopment,inventedonlyaboutsixthousandyearsago.Speechisusuallyinformal,whilethewordchoiceofwriting,bycontrast,isoftenrelativelyformal.Althoughpronunciationandaccentoftentellwherethespeakerisfrom,theyareignoredinwiringbecauseastandarddictionandspellingsystemprevailsinmostcountries.Speechreliesongesture,loudness,andtheriseandfallofthevoice,butwritinglacksthesefeatures.Carefulspeakersandwritersareawareofthedifferences．4．有损连贯性的几种情况：考生在写作中经常出现下面几种错误：1）不必要的改变时态Inthemovie,RobertRedfordwasaspy.Hegoestohisofficewherehefoundeverybodydead.Otherspieswantedtokillhim,sohetakesrefugewithJulieChristie.Atherhouse,hehadwaitedfortheheattodiedown,buttheycomeafterhimanyway.2）不必要的改变单复数Everybodylooksforsatisfactioninhislife.Theywanttobehappy.Butifheseeksonlypleasureintheshortrun,thepersonwillsoonrunoutofpleasureandlifewillcatchuptohim.Theyneedtopursuethedeeperpleasureofsatisfactioninworkandinrelationships.3）不必要的改变人称Nowmorethanever,parentsneedtobeintouchwiththeirchildren'sactivitiesbecausemodernlifehasthetendencytocausecleavagesinthefamily.Youneedtoarrangefamilylikeitsothatfamilymemberswilldothingstogetherandknowoneanother.Youneedtogiveupisolatedpleasuresofyourownandrealizethatparentshaveasetofobligationstosponsortogethernessandthereforesponsorknowledge.因此写作中，一定要注意时态，人称以及数的变化是否正确，要注意保持一致。怎样写好英语段落段落是文章的缩影。写好了段落，就能比较成功地写出较好的文章。经过中学英语基础阶段的学习之后，大学英语的写作重点就从选词造句转移到了联句成段和联段成篇上。进行段落层次上的写作训练，是写好英语文章的关键一环。下面介绍的是段落结构。段落（paragraph）是由表达单一中心思想（controllingideaorcentralidea）的一组句子（包括主题句topicsentence,推展句supportingsentences及结论句concludingsentence）构成，是文章结构的基本独立单位。我们将就主题句和中心思想这两个方面展开讨论。一般段落的构成可以是：主题句拓展句1拓展句2（拓展句3）结尾句即：首尾强调段落重点，中间展开阐述。有时段落还会有过渡句，结构成为：6主题句拓展句1过渡句拓展句2（拓展句3）结尾句主题句与推展句1．主题句主题句（topicsentence）是表达段落主题的句子。它用以概括段落大意，要求全段其他文字都围绕它展开。请看下例：Mymotherhaspassedalongtomecertainrulesforgettingalongwithothers.Don'targuewithparents;theywillthinkyoudon'tlovethem.Don'targuewithchildren;theywillthinkthemselvesvictimized.Don'targuewithspouses;theywillthinkyouareatiresomemate.Don'targuewithstrangers;theywillthinkyouarenotfriendly.Mymother'srules,infact,canbesummedupintwowords:Don'targue.主题句中提出的"certainrules"指的是什么？展开句中通过四个"Don'targue--"逐一加以交代。从结构来看，这是一个比较典型的段落，它包括了主题句，推展句和结论句（即1）主题句的位置主题句通常放在段落的开端，其特点是开门见山地摆出问题，然后加以详细说明。其作用是使文章的结构更清晰，更具说服力，便于读者迅速地把握主题和想象全段的内容。主题句可以放在段中起到承上启下的作用，或放在段尾起概括全段的作用。但初学者比较难于掌握，因而学生应尽量采用将主题句放在段落开头的写作手法。例1:Ourlifetodaydependsverymuchonenergy.Intownsandinvillages,onfarmsandinfactories,machineshavemadelifeeasierthanitusedtobe.Themachinesuseenergy,andenergyisneededforheating,lighting,communications,carryinggoods--everything.Factoriesandindustrialplantsuseagreatdealofenergytomakethethingsthatweuseandbuyandsell.这段文字所讲的主要是能源问题。第一句就概括性地提出“我们目前的生活很大程度上依赖于能源”。而随后出现的三句都是具体事例，对第一句进行说明和论述。我们可以断定第一句为该段的主题句。例2:（主题句）Noonecanavoidbeinginfluencedbyadvertisements.（推展句1Muchaswemayprideourselvesonourgoodtaste,wearenolongerfreetochoosethethingswewant,foradvertisingexertsasubtleinfluenceonus.（推展句2）Intheireffortstopersuadeustobuythisorthatproduct,advertisershavemadeaclosestudyofhumannatureandhaveclassifiedallourlittleweakness.以上这段由三句话组成。第一句是主题句，直截了当指出无人不受广告影响这个主题，接着列举两个推展句对其补充和支持，指出我们已无法自由选择所需的商品，理由是广告商已仔细研究了我们的心理，并完全掌握了我们的弱点。句子衔接自然，步步紧扣主题。2）如何写好主题句中的关键词段落的主题句对主题的限定主要是通过句中的关键词来表现的。关键词要尽量写得具体些。对“具体的要求包括两个方面：一是要具体到能控制和限制段落的发展；二是要具体到能说明段落发展的方法。准确地把握关键词是清楚地表达段落主题、写好段落主题句的重要12dependsverymuchonenergy;noonecanavoidbeinginfluenced.我们再看下列例句：原句1.Hecanfixabicyclehimself.斜体部分应为主题句中的关键词。但它只是限制了段落发展的部分内容，并没有告诉读者该用哪种方法展开，是用因果关系法还是用分类法？修正：Hecanfixabicyclehimselfinseveralsimplesteps.修正：Thereareseveralreasonswhyhecanfixabicyclehimself.7原句2.Shetriestoimproveherlooks.斜体部分应为主题句中的关键词。她试着改变她面容的理由是什么？或者她采取什么方法来改善呢？我们无法从关键词中清楚得知。修正：Shetriesmanywaystoimproveherlooks.修正：Therearesomereasonswhyshetriestoimproveherlooks。3）如何写好主题句的中心思想主题句由两部分组成，即主题(topic)和中心思想（controllingidea是导向(control)和制约(limit)段落的发展脉络，所谓制约就是限制主题的覆盖范围，两者不可分割。没有导向，内容就会离题或偏题；没有制约，内容就可能超出一个段落所能容纳的范围。对于初学写作的人来说，“导向”的重要性容易理解，但如果由他们自己来构思一个主题句，就可能忽视“制约”这一面。例如：Therearetwowaysinwhichonecanownabook.Thefirstisthepropertyrightyouestablishbypayingforit,justasyouhavemadeitapartofyourselfandthebestwaytomakeyourselfapartofitisbywritinginit.本段的主题句如果没有inwhichtwoways不仅不能起制约作用，而且也不能起导向作用，句子本身读起来也就使人觉得欠缺点什么。Exerciseisbeneficialtoyourheart.A22-yearstudywasconductedbydoctorsinCalifornia.Theyfoundthatpeoplewhoworkatphysicaljobsexperiencefewerheartattacksthanotherpeople.Theseactivepeopleworkallthetimeatmoderatespeeds,theirdailyroutinegivesthemanadequateamountofexerciseandhelpsthemstayinshape."Exerciseisbeneficial"这是毫无疑义的。但主题句中如不加上"toyourheart"来加以control和limit，那就流于空泛。controllingidea2．推展句1）主要推展句主要推展句(majorsupportingstatement)的主要特点是：围绕段落主题句展开的每一个推展句本身都不要求作进一步的说明或证明，句与句之间的关系是相互独立又是互相连接的。例1(主题句)Thereareseveralfactorsaffectingclimate.(推展句1)Onefactoristheamountofsunlightreceived.(推展句2)Altitude,ortheheightabovesealevel,alsodeterminescli