说明文的写法

爱问共享资料拥有大量关于说明文的写法.doc的实用类文档资料，所有文档由知名合作机构以及专业作者提供，线上总资料超过两个亿，保证满足您的需求。

说明文的三种写作方法与练习A分类法分类法就是按一定的标准把要说明的对象分成若干类,分别加以说明。分类法的写作步骤:段首句点明主题→分别列举内容→得出合理的结论。分类法的写作要领:①被说明的对象必须是同属不同类或同类不同种的事物,不同属、不同类的事物不能用分类法。②分类标准必须统一,不可中途变更标准。分类法常用的关键词:firstly,secondly,finallylastly,kind,sort,variety,include,involve,exclude,class,classify,contain,likewise,inaddition,furthermore,besides,conclusion请看下面一则短文:typewritersWhetheryouworkathomeorrunasmallbusiness,ordopersonalcorrespondence,thelatestdevelopmentinofficeequipmentswillproveusefulandconvenientWithsomanydifferenttypewriterstochoosefromthesedays,youcaneasilyfindaproperoneThebasicformoftypewriteristhemanualtypewriterMostofthemarelightweightmachineswithfewmovingpartstogowrong,andtheyarereasonablyinexpensivePerfectlyadequateformosthouseholdpurposes,manualtypewritersareespeciallyusefulforstudentsandbeginnersUnlikemanualmachines,anelectrictypewriterhasanelectricmotorThismeansyoucangetcharactersregardlessofthepressurewithwhichyoustrikethekeysThesemachinesaremoreconvenientthanthemanualonesThemostadvancedtypewriter,themultiprinter,ishardlyrecognizedasatypewriterItisalightweight,silentlyoperatingmachinewhichproduceshighqualityprintingbymeansofsmalldotsItisahighlyadaptablemachinewiththecapacityformanyfunctionsbesidesthatofsimpletypingThis,togetherwithitsreliability,canmakeitextremelyusefulinthebusinesssituationHowever,inchoosingatypewriter,first,themachineshouldmeetyourneeds,andsecond,youshouldpaymoreattentiontowhichonebestsuitsyou分析:本文在第一段点明主题:在很多种打字机中选择适合自己的一种是很重要的,在接下来的三段里,分别说明了手动打字机themanualtypewriter、电动打字机theelectrictypewriter和多功能打字机themultiprinter的性能和特点。最后一段得出结论:根据自己的实际需要选择合适的打字机。整个文章的思路明确、条理清晰。B解释法简单地说,解释法就是说明"如何做某事,某事物如何工作"的一种说明方法。解释法的写作步骤:过程第一步→第二步→第三步……解释法的写作要领:在写作的过程中,应按照解释说明的顺序,一环扣一环地安排资料,不要节外生枝,插入其它细节,以保持整个过程的连贯性。解释法常用的关键词:①Thefirststep→thesecondstep→thethirdstep→finally②Tobeginwith→then→finally③Start→until→then→finally请看下面的短文:MakingBreadTherearefourseparatestagesinmakingbreadThefirststagebeginsbymixingyeast酵母withwarmwaterThismixtureisthenaddedtohalftheamountofthepreparedflourTheresultantbatter面团mixtureisthenleftforanhourAtthenextstagetherestoftheflourisaddedtotherisenbattermixture,alongwithsugarandoilThemainstepinthesecondstageisathoroughkneading揉成团ofthedough,afterwhichitislefttoriseThethirdstageinvolvesshapingthedoughintoloavestheshapedloavesarethenputintobreadtinsInthefinalstagethebreadisbakedinahotovenThewholeprocessofbreadmakingfinisheswhenthebreadistakenfromtheovenandlefttocoolonracks从这则短文中,可以看出"制作面包"的整个过程:第一步是用酵母和好面,第二步在"发了的面"therisenbattermixture里加进面粉、糖和油,然后揉成团,让它再次"发"起来,第三步把面团做成面包状,然后放进面包烤模breadtin里,最后一步是把它们放在烤箱内加热,然后拿出来放到架子上,使它们变凉。整个过程清楚明了,即使从来也没有做过面包的人也可以动手试一试了。C举例法举例法就是用举例的方式来说明复杂的事物,这类作文的题目往往是:怎样理解……,为什么说……,试举例说明……,其要说明的内容往往是社会生活中人们对某些事物或现象的看法。举例法的写作步骤:给出主题句→用举例的方式来说明→结尾重述主题。举例法常用关键词:forexample,forinstance,suchas,namely,thatistosay,frequently,especially,ingeneral,inparticular,toillustrate请看短文:TheOlder,theWeakerMindManyofusbelievethatapersonsmindbecomeslessactiveashegrowsolderButthisisnottrue,accordingtoDrJarvik,professorofPsychiatryattheUniversityofCaliforniaShehasstudiedthementalfunctionsofagingpersonsforseveralyearsForexample,oneofherstudiesconcernedpairsofidenticaltwins,whowerefirstexaminedwhentheywerealreadyyearsoldAsDrJarvikcontinuedthestudyofthetwinsintotheirsands,theirmindsdidnotgenerallydeclineaspeoplethoughtHowever,therewassomedeclineintheirpsychomotorspeedThismeansthatittakesthemlongertoaccomplishmentaltasksthanitusedtoButwhenspeedwasnotconsideredtobeafactor,theylostverylittleintellectualabilityovertheyearsIngeneral,DrJarviksstudieshaveshownthattherewasnodeclineinknowledgeorpowerofreasoningThisistruenotonlywiththoseintheirsands,butwiththoseintheirsandsItistruethatolderpeoplethemselvesoftencomplainthattheirmemoryisnotasgoodasitoncewasHowever,muchofwhatwecall"lossofmemory"isnotthatatallForexample,theolderpersonperhapshadtroubleinhearingandseeing,orwastryingtolearnthenewthingatafastpaceAlthoughtheirmindseemstodecline,itisnotnecessarilyasignofdeclineduetooldageOftenitissimplyasignofadepressedemotionalstate分析:第一段引出话题:人的脑力与年龄无关,第二段利用博士的研究实例进行了说明,最后一段得出结论:脑力的变化与年龄无关,完全是人的情感影响所至。如何写好描写文二、描写文常用方法:第一是在日常谈话或商业广告中对有关对象的某些主要特征加以简要描写,这种描写方法叫做PopularMethod。第二是在旅游胜地介绍和小说中对有关对象的多方面特征加以合理组织和富有技巧的描写,从而推出鲜明丰满的艺术形象,这种描写叫做ArtisticMethod。第三是在科技文章中对有关对象的特性加以完整、准确的描写,如同摄影和复印一样,目的给人以真实的印象,这种描写叫做ScientificMethod。第四是在诗歌和其他一些文艺作品中通过描写激发读者的联想,并通过自己的想象得到艺术享受和启迪,这种描写叫做SuggestiveMethod。当然,这四种方法是最基本的,不可能截然分开,在实际使用中会互相渗透。三、写好描写文的两个关键好的描写一定要抓住两个关键:突出印象和丰实细节。试比较下面两个描写主题句:ThestudentloungeisaplacewherestudentscongregateinaleisurelyfashionandasaconsequenceitisnotalwaysattractiveandneatThestudentloungeisamessyroom上述句过于松散,主题被冲淡了,给读者的印象模糊,而句简练有力,messy一词立刻抓住了读者的注意力:怎么样的一个messyroom呢接下去就是要作好细节描写。如照上述句进行描写,就要紧紧围绕messy着笔,不要写学生如何做功课,也不要写墙上有什么色彩画报,而要写诸如吐在地毯上的橡皮糖,肮脏的桌子上抛下的蛋壳、面包皮,等等。