平行结构（parallel structure）的句子在英语语言中占据了异常重要的地位。平行结构是由两个或者两个以上的句法结构相同或相似、意义相关、语气一致的语言单位所组成。
它是为提高语言表达能力而运用的一种简洁明快的修辞手法。在演讲中运用这种结构尤其会使演讲铿锵有力，节奏明快且有较强的影响力和感染力。在雅思写作中运用这种结构可扩展句式，展示强大的词汇量。
（一）平行结构注意点：
1．语法结构要一致。
如果平行结构中前面是doing，后面也是doing；如果前面是名词，后面也要是名词，不能为to do；如果前面平行的是that从句，后面也要跟一个that从句。
2．平行的对象要属性一致。
如果平行结构的前面是人，那后面也应该是人，性质上应该相似。
（二）平行结构标志词：
A and B
both A and B
A or B
either A or B
not A but B
not only A but also B
A rather than B
from A to B
《剑桥雅思真题4》Test 1 Passage 1 Question 2
But Salikoko Mufwene, who chairs the Linguistics Department at the University of Chicago, argues that the deadliest weapon is notgovernment policy but economic globalization.
但是，芝加哥大学的语言学系主任Salikoko Mufwene认为，最致命的武器不是政府政策，而是经济全球化。
《剑桥雅思真题5》Test 2 Passage 3 Question 31
In Britain, moreover, scientists worried that English had neither the technical vocabulary nor the grammatical resources to express their ideas.
此外，在英国，科学家们担心英语既没有技术词汇，也没有语法资源来表达他们的想法。
《剑桥雅思真题6》Test 4 Passage 3 Question 39
Work in the playground is important, too. One helpful step is to train lunchtime supervisors to distinguish bullying from playful fighting, and help them break up conflicts.
在操场上的工作也很重要。其中一个有益的步骤是训练午餐时间的主管，让他们区别欺凌和嬉闹式打闹，并帮助他们解决冲突。
《剑桥雅思真题7》Test 2 Passage 2 Question 26
He feels this would help to change the attitudes of both consumers and farmers .
他认为这将有助于改变消费者和农民的态度。
《剑桥雅思真题8》Test 1 Passage 3 Question 34/35
Positive results could be produced by factors such as sensory leakage or outright fraud.
积极的结果可能是由感觉泄漏或直接欺诈等因素造成的。
《剑桥雅思真题8》Test 2 Passage 2 Question 20
We can deduce that the Little Ice Age was a time of climatic shifts,rather than of consistent freezing.
我们可以推断，小冰期是气候变化的时期，而不是持续的冻结。
《剑桥雅思真题9》Test 4 Passage 1 Question 11
One of Marie Curie's outstanding achievements was to have understood the need to accumulate intense radioactive sources, not only to treat illness but also to maintain an abundant supply for research.
Marie Curie的一个显著成就是，他明白需要积累大量的放射性物质，不仅是为了治疗疾病，而且还为研究提供了充足的供应。
（三）平行结构的种类：
在一个句子里面，任何成分都可以构成平行结构，常见的平行形式中的词性包括：动词、名词、形容词、介词、从句、不定式、分词等。
《剑桥雅思真题7》Test A Section 3
The dog must persevere and maintain focus for hours at a time.（动词并列）
狗狗必须坚持并保持数小时的注意力。
《剑桥雅思真题7》Test A Section 3Over
the sound of roaring engines, rushing air vents and grindinggenerators, a dog barks.（现在分词并列）
在隆隆的引擎声、急速的通风口声和刺耳的发电机声中，一只狗在吠叫。
《剑桥雅思真题7》Test A Section 2
Health and Safety laws provide basic guidance on how much room is required per office desk or manufacturing operation.（名词并列）
健康和安全法规提供了基本的指导，关于每个办公桌或生产操作需要多少空间。
《剑桥雅思真题7》Test 4 Passage 1
The instant the sail opened into the wind, a huge force was generated and the column was raised to the vertical in a mere 40 seconds.（被动句并列）
当帆迎风打开的那一刻，一个巨大的力量产生了，柱子在仅仅40秒内就垂直上升了。
《剑桥雅思真题7》Test 3 Passage 3
Loss of leaves from trees should be more extensively and carefullymonitored.（副词并列）
应该更广泛和更仔细地监测树木叶子的掉落。
《剑桥雅思真题7》Test 3 Passage 3
This means that a forest policy is vital, that it must transcend national frontiers and generations of people, and that it must allow for the inevitable changes that take place in the forests, in needs, and hence in policy.（that从句并列）
这意味着森林政策是至关重要的，它必须超越国界和几代人，它必须考虑到在森林中、在需要中以及因此在政策上发生的不可避免的变化。
《剑桥雅思真题7》Test 3 Passage 3
As a whole, European countries see forests as performing a triple function: biological, economic and recreational.（形容词并列）
作为一个整体，欧洲国家认为森林具有三重功能：生物、经济和娱乐。
《剑桥雅思真题4》Test 1 Passage 1
The aim of the present study is to start to provide such information, to help teachers design their educational strategies to build upon correct ideas and to displace misconceptions and to plan programmes in environmental studies in their schools.（to do结构并列）
本研究的目的在于提供这些资讯，协助教师设计教育策略，以建立在正确的观念上，取代错误的观念，并规划学校的环境研究课程。
《剑桥雅思真题7》Test 2 Passage 1
The disastrous Hanshin earthquake in 1995 killed 6,400 people, toppledelevated highways, flattened office blocks and devastated the port area of Kobe.（动词过去式并列）
1995年灾难性的阪神大地震夺去了6400人的生命，掀翻了高架公路，夷平了办公大楼，摧毁了神户的港口地区。
《剑桥雅思真题7》Test 2 Passage 2
The cost is in the collateral damage of the very methods of food production that have made the food cheaper: in the pollution of water,the enervation of soil, the destruction of wildlife, the harm to animal welfare and the threat to human health caused by modern industrial agriculture.（名词短语并列）
代价就在于使食品价格低廉的各种食品生产方法所带来的附带损害：现代工业化农业造成的水污染、土壤的腐败、野生动物的破坏、对动物福利的损害以及对人类健康的威胁。
《剑桥雅思真题6》Test 2 Passage 2
Elderly people are growing healthier, happier and more independent,say American scientists.（比较级并列）
美国科学家称，老年人正变得更健康、更快乐、更独立。
