考研英语写作的题材与我们日常生活息息相关，通常涉及事物间的比较，说明其相似性和相异性、事物之间的因果关系，有时要求考生分析事实，找出原因或解决问题的方法，或对一个问题提出个人看法等，所以，考生在复习时，要尽可能熟悉和掌握表达这些关系的常用句型：（1）相似性AistoBwhat/asCistoD（A之于B犹如C之于D）e.g.MoralcorruptionistotheStateasphysicaldiseaseistoanindividualbody.Classicmusicistomygenerationwhatpopsaretohergeneration.Justas…，so…（正如……，……也如此）e.g.Justaswoodsareindispensabletobirds，soistheearthtohumanbeings.Justastheymustputasidetheirprejudices，sowemustbepreparedtoaccepttheirgoodfaith.AandBhavesomethingincommon（A和B有共同之处）e.g.Ashumanbeings，theAmericanandChinesehavelotsofthingsincommon.TomandIhavebackgroundincommon.AissimilartoB（A与B相似）e.g.Myhobbyissimilartohisinthatwebothlikecollectingrecords，foreignanddomestic.Myproblemsareverysimilartoyours.Thesameistrueof…/Thesamecanbesaidof…（……也是如此）e.g.Astheeconomiesofallcountriesarecloselyinterrelatednocountrycandevelopinselfseclusion.ThesameistrueofChina.（2）相异性Aisjusttheopposite（toB）（A和B正相反）e.g.Beijingispopulousandcrowded，whileCanberraisjusttheopposite.Adiffers（isdifferent）fromBinthat…（A不同于B在于……）e.g.China’sconditiondiffersfromoursinthatChinahasthelargestpopulationintheworld.ThefamilysedansmadeinChinaaredifferentfrom/thanthosemadebytheAmericans.Theyaremorecompactandenergysaving.…（Thecase）isnotthesame（……是不相同的）e.g.Whileitmaybetruethatbasketballandvolleyballsharecertainfeatures，theexcitementeacharousesinthespectatorsisnotthesame.Thedevelopmentzonesintheeasterncoastalareasaremostlyinitiatedandsupportedbygovernments，butthecaseisnotthesamewiththoseinthewest.Contraryto（Onthecontrary）…（正相反）e.g.Contrarytoourestimation，theeconomicsituationofthecountryisgraduallygettingbetter.TheyaskedmeifIhadfinishedthejob.Onthecontrary，Ihaveonlyjustbegun.（3）权衡Theadvantagesoutweighthedisadvantages.（利大于弊）e.g.Itseemssafetosaythattheadvantagesofmarriageoutweighthedisadvantagesofdivorce.Asisshownbythearguments，thedrawbacksofcloningtechnologyoutweighitspromisingadvances.Nothingcanrival…/Thereisnorivalto…（……是无与伦比的）e.g.Perhapsnothingcanrivalthepleasurefromreading.Th