同等成分的一致
　　1.句子的同等成分应该在结构上保持一致
　　如：误：Sleep, rest and relaxed are the best remedies for many headaches.
　　正：Sleep, rest and relaxation are the best remedies for many headaches.
　　睡眠、休息和娱乐是治疗多种头疼的最好办法。
　　2.在比较结构中，被比较的事物应该是同等成分。
　　如：误：The climate of Beijing is not so pleasant as Dalian.
　　正：The climate of Beijing is not so pleasant as that of Dalian.
　　北京的气候不如大连的好。
　　二.省略
　　为了避免重复，使语言简练紧凑，在不起误解的情况下，将一个句子中一个或多个成分省去，这样的句子叫做省略句。
　　1.省略主语
　　通常用在祈使句或口语中的固定表述中。
　　如：Have a good time.愿你过得愉快!
　　Hurry up!快一点。
　　2.省掉行为动词或系动词
　　如：Sophia is brighter than her brother.苏菲亚比她弟弟聪明。(brother后面省略了is)
　　Some of us study French, others German.我们有的学法语，有的学德语。(others后面省略了study)
　　3. 省略表语
　　如：Are you ready?
　　Yes, I am.(am后面省略了ready)
　　4.同时省略句子几个部分
　　如：She likes reading better than going to parties.她爱读书而不爱去参加聚会。(than后面省略了she likes)
　　Have you ever been to Hong Kong ?
　　Never.(=I have never been there)
　　You are a college student, aren’t you? ( =aren’t you a college student?)
　　Has she gone or not? (=Has she gone or has she not gone?)
　　注：在以if, when, where, though, as, as if等连词引导的从句中，如果从句中的动词是be, 可以将主语和动词be省掉。
　　如：Fill in the blanks with the given words. Change the form where necessary.
　　用所给的词填空，必要的地方可以改变其形式。(where之后省略it is)
　　He looks as if drunk.他看起来好像是喝醉了酒似的。(=as if he were drunk)