1．简洁性（Conciseness）1.2避免不必要的重复(chóngfù)，包括语义重复(chóngfù)和同词重复(chóngfù)。Sheisattractiveinappearance,butsheisaratherfoolishperson.Sheisattractive,butratherfoolish.2.多样性（Variety）2.1.1既可以(kěyǐ)用主动式也可以(kěyǐ)用被动式，如：Wecertainlyshouldmakegreatefforts.Greateffortsarecertainlyrequired.2.1.2既可以用肯定(kěndìng)式也可以用否定式，如：Thelessonwillbefirmlyrootedinourminds.Wewillneverforgetthislesson.2.1.3既可以(kěyǐ)是正常语序也可以(kěyǐ)是倒装语序，如：Onecan’tlearnanythinguntilheridshimselfofcomplacency（自满）.Onlywhenoneridshimselfofcomplacencycanhelearnsomething.2.1.4某些(mǒuxiē)成分既可以放在句子前面也可以放在句子后面，还可以放在中间，如：Withacar,peoplecangetaroundfreely.Peoplecangetaroundfreelywithacar.People,withacar,cangetaroundfreely.2．2句子(jùzi)长度的多样性Whenshereturnedtoheroffice,shefoundanotefromMr.Mayunderthedoor.Hesaidthathehadbeenwaitingforherintheparkbutdidn’tfindher.Hewassorryforthat.Shereturnedtoheroffice.ShefoundanoteItwasfromMr.May.Itwasunderthedoor.Hesaidhehadbeenwaitingforherinthepark.Hedidn’tfindher.Hewassorryforthat.3．统一性（Unity）3.1Thepolicehelpedhimwhenhisimportantdocumentswerelostandhefoundthemseveraldayslater.句子的统一性原则(yuánzé)要求句子只有一个明确的中心。此句有两个中心thepolice和he,最好改为：Helosthisimportantdocuments,butfoundthemwiththehelpofthepoliceseveraldayslater.3.2Forexample,theincreaseinthecostofrentingahouse.此句只有名词短语而无谓语动词，结构不完整，不能作为一个独立的句子来看待(kàndài)。应改为：Forexample,thecostofrentingahousehasincreased.4.连贯性（Coherence）4.2Mymotherisamusician;thereforeIhavealsochosenitasmyprofession.Mymotherisamusician;thereforeIhavealsochosenmusicasmyprofession.代词起连接语篇的作用，它能体现句子之间的逻辑联系，上面句中it指代不明(bùmínꞬ)，模棱两可。4.3Aftereatingourlunch,thedrivercalledustothebus.Aftereatingourlunch,wewerecalledtothebusbythedriver.此句非谓语动词的逻辑(luójí)主语与主语不一致。这显然不是作者的原意，改正后的句子就清楚多了。4.4Thebasketballplayersweredisappointed,causedbythesuddenchangeofweather.Thebasketballplayersweredisappointedbecausetheweathersuddenlychanged.此句caused引出的分词短语与前半句没有意义联系，导致短语失去(shīqù)修饰对象而呈游离或垂悬状态，从而破坏了整个句子的逻辑连贯性。5．强势(qiánꞬshì)性（Emphasis）Theinhabitantsofthecitywererobbed,st