在重复表达相同意思的时候,句子形式需要变化,这样不会显得单调。When repeating a statement to emphasize it, the writer may need to vary its form. Otherwise, the writer should follow the principle of parallel construction.如果几个句子成分在内容和功能上相似,让它们具有相似的表达形式可以达到更好的阅读效果。这就是英文中的平行结构(parallel construction)。This principle, that of parallel construction, requires that expressions similar in content and function be outwardly similar.例1:Formerly, science was taught by the textbook method, while now the laboratory method is employed.分析:前半句和后半句在意思上是对应的,可是前面是science作主语,后面又是the laboratory method作主语;后半句的主语对应的是前半句的宾语。对比的效果不太好。这里考虑使用parallel construction,让它们有相似的结构,来加强这种对比的效果,如下:建议修改为:Formerly, science was taught by the textbook method; now it is taught by the laboratory method.这样是不是感觉表达简明有力了;前后部分句型相似,而且不需要任何连词,一个分号就搞定了。分号在英文论文写作中非常管用,如果我们觉得两个句子意思相关,但由于前面已经用了and之类的连词而不想再用这些连词了,可以考虑使用分号。一组单词中的每一个单词都和某一个冠词或介词搭配时,这个冠词或介词要么只出现在第一个单词前,要么出现在每个单词前。说起来太拗口,直接看例句吧:例2:The treatment group, the model group, and control group had ….分析:像上面这样就不行了,一会儿有the一会儿没the的,要改成下面这样:建议修改为:The treatment group, the model group, and the control group had ….或者The treatment group, model group, and control group had … (第一个the把后面全管了)例3:in spring, summer, or in winter分析:上面这样也不行,一会儿有in一会儿没in的,要改成下面这样:建议修改为:in spring, summer, or winter 或者in spring, in summer, or in winter)有些词常和介词搭配,如果多个这样的词并列使用时,每一个词所对应的介词都不能省,除非这几个词对应的介词一样。直接看例句吧:例4:His speech was marked by disagreement and scorn for his opponent's position.分析:disagreement和with搭配,所以这里不能把with省略了,要改成下面这样:建议修改为:His speech was marked by disagreement with and scorn for his opponent's position.留学生英文论文代写“both, and”、“not, but”、“not only, but also”、“either, or”、“first, second, third”等常用搭配要接相同的结构,举例如下:例5:It was both a long ceremony and very tedious.分析:both后是名词,而and后是形容词,词性要相同建议修改为:The ceremony was both long and tedious.例6:A time not for words but action.分析:but后加上for才对称建议修改为:A time not for words but for action.例7:Either you must grant his request or incur his ill will.分析:把either放到must后,句子结构更清晰建议修改为:You must either grant his request or incur his ill will.例8:My objections are, first, the injustice of the measure; second, that it is unconstitutional.分析:first后是名词,而second后是句子,不对称建议修改为:My objections are, first, that the measure is unjust; second, that it is unconstitutional.