词汇的理解对阅读的意义不言而喻。但个别词不认识并不妨碍理解，有时遇到生词还要学会跳过去。除了其他破解词义的方法外，根据上下文的线索寻找等价或反义结构是一个很有效的方法。所谓等价结构，就是意义相同的结构。而反义结构就是意义相反的结构。对文章中的一个部分不理解时，可以根据这一部分的上下文判断意义。上下文有时和不理解的部分构成同义关系，不理解部分的意义就是上下文的意义。反之，上下文有时和不理解部分构成反义关系，那么，不理解部分的意义就是上下文意义的反面。等价结构包含多种，本文主要介绍并列结构。一般而言，并列结构常表示并列的两部分意义相同。本文讨论的反义结构主要是包含连词如but， while等的结构，它们常表示两部分意义相反。下面以2005年考研阅读的文章为例说明如何根据等价结构或反义结构把握句子意义。

　　一、等价结构

　　Text 1（2005）

　　Everybody loves a fat pay rise. Yet pleasure at your own can vanish if you learn that a colleague has been given a bigger one. Indeed,if he has a reputation for slacking,you might even be outraged. Such behavior is regarded as all too human, with the underlying assumption that other animals would not be capable of this finely developed sense of grievance.

　　[分析] 等价结构一：fat 呼应bigger

　　等价结构二：outraged=grievance（两句之间是递进结构）。

　　等价结构三：“all too human”=other animals would not be capable of this finely developed sense of grievance（逗号之后为解释）

　　And if one received a grape without having to provide her token in exchange at all， the other either tossed her own token at the researcher or out of the chamber， or refused to accept the slice of cucumber. Indeed， the mere presence of a grape in the other chamber （without an actual monkey to eat it） was enough to induce resentment in a female capuchin.

　　[分析] 等价结构：resentment=Indeed之前句子所表达的意思，因为Indeed表示递进。

　　Feelings of righteous indignation， it seems， are not the preserve of people alone.

　　[分析] 等价结构：preserve= alone（由not…alone结构可知）。

　　However,whether such a sense of fairness evolved independently in capuchins and humans,or whether it stems from the common ancestor that the species had 35 million years ago, is, as yet, an unanswered question.

　　[分析] 等价结构：stems from=evolved（or连接并列结构）。

　　Text 3（2005）

　　And one leading authority says that these intensely powerful mental events can be not only harnessed but actually brought under conscious control, to help us sleep and feel better.

　　[分析] 等价结构：harnessed=brought under conscious control（not only…but连接递进结构）。

　　Text 4（2005）

　　Mr. McWhorter’s academic specialty is language history and change,and he sees the gradual disappearance of “whom”， for example， to be natural and no more regrettable than the loss of the case-endings of Old English.

　　[分析] 等价结构：no more regrettable=natural （and连接并列结构）

　　Equally,in poetry,the highly personal,performative genre is the only form that could claim real liveliness.

　　[分析] 等价结构：genre=form（表语结构提示意义相同；实际上，genre与form之间是种属关系，genre是一种form）

　　he is really grieving over the loss of something beautiful more than useful

　　[分析] 等价结构：grieving=loss of something beautiful（对美丽事物的消失，一般应该感到惋惜，由此可知grieving的意思就是“惋惜”）。

　　二、反义结构

　　Text 1（2005）

　　when two monkeys were placed in separate but adjoining chambers

　　[分析] 反义结构：separate 与adjoining意思相反（二者由but连接）

　　Text 4（2005）

　　While even the modestly educated sought an elevated tone when they put pen to paper before the 1960s.

　　[分析] 反义结构：elevated 与modestly意思相反（句首的while even提示相反意义）。(责任编辑：wotersion)