平行结构
平行结构作为考点的出题率奇高，平均每套题中都有2-4道题目，因此必须引起高度重视。平行结构指的就是并列成分，不难理解和掌握。只要形成对and, or等词的敏感，牢记上面的固定搭配使用的并列连词(both…and, as well as 等)，一看到这些词就首先考虑平行结构，无论作填空还是改错都是行之有效的方法。
平行结构可能是并列的名词、形容词、不定式、动名词、谓语动词、分词等
例题：
(1)
During most of this century, A. Philip Randolph struggled for Black rights in the United States and becomes an important figure in the labor movement.
应改为：became.
解释：and连接两个并列谓语, 前者是过去时(struggled), 后者应相呼应使用过去式。
注意：在同一个时间背景下(本题中是During most of this century )，平行结构连接词所对应的动词必须采取一致的时态
(2)
Classicism as a doctrine seeks what is universally truth and good.
应改为：true.
解释：and连接两个并列表语, 词性必须相一致, good是形容词, 此处truth也应该用形容词true。
注意：平行结构连接词所对应的各个连接单位的词性必须相一致，再如例题4
(4)
It is more difficult to write simply, directly, and effective than to employ flowery but vague expressions that only obscure one’s meaning.
应改为：effectively.
解释：句中and连接的是几个修饰动词write的副词, 它们的结构应是平行的. effective是形容词, 无法与simply, directly并列使用
(5)
Before pioneers cleared the land for farms, cities, and road, forests covered about 40 percent of what is now the state of Illinois.
应改为：roads
解释：and连接作为for的并列宾语，和farms, cities平行的应是复数名词roads
注意：平行结构连接词所连接的名词，其单复数形式必须相同，除非有的式可数名词，有的是不可数名词。
(5)
Lillian D. Wald, public health nurse and ----, was born in Cincinnati Ohio, in 1867.
(A) reforming society
(B) social reformer
(C) who reformed society
(D) her social reform
答案：B
解释：and连接的是主语Lillian D. Wald(人名)的两个并列同位语, public health nurse 是形容人的名词词组, 需填的部分应与其一致, A属分词词组, C属定语从句,D虽是名词词组, 中心词是reform,它们均不符合题意.
注意：平行结构连接词所连接的几个单位在结构上，形式上应该尽量一致，比如上题的
public health nurse and social reformer, 都是形容词修饰名词。 再如例题6
(6)
Western Nebraska generally receives less snow than eastern Nebraska is
应改为：Nebraska does
解释：题目中实际上是两个句子在用than连接进行比较， 它们比较的内容是receives the snow, 因此D中应该用does而不是is 来代替前面的receives