如何扩展英语段落写作的方法
段落的扩展，就是在一个段落中如何根据主题句中的主导思想(controlling idea)来阐述问题的方法。换句话说，段落的扩展是指选用一些有关的细节来引申、说明、论证主题句。
如何扩展英语段落写作的方法
以下介绍几种有效的段落扩展方法：
1 举例法(examples)
举例就是用具体生动的事例来阐述作者的观点和见解的一种最简捷、最有效的方法。也就是说，它用具体的事例来阐述主题句中的主导思想。用具体的事例来扩展主题句是最常用的写作方法之一。它不仅使文章通俗易懂，而且还给读者留下深刻印象，使文章更具有说服力。在选择例证时要选择最能支持你的观点，最有说服力的句子。例子的多少主要由文章的长短而定。
[例]
Sports and games do a lot of good to our health. They can make usstrong, prevent us from getting too fat, and keep us healthy. Especiallythey can be of great value to people who work with their brains most ofthe day, for sports and games give people valuable practice in exercisingthe body.
例子中的第一句是主题句，即sports and games do a lot of good toour health.在此主题句中的主导思想是a lot of good.以下事例都是来进一步阐述主题中的主导思想的，即用具体事实来支持主题句中的观点。
2 定义法(definition)
这了避免混乱和误解，写作时应对读者不熟悉或有多种解释的单词、术语、概念下定义;所以定义法是文章写作中常见的一种方法。定义法主要以下几种方法：
2.1 运用同义词或词组来解释某一术语或新词。例如：
To mend means to repair.
2.2 用含有定语从句的句子为术语下定义。以定语从句下定义是最普遍的手段。这种手段一般包括三个组成部分：A 术语(term);B 术语所属的类别(class);C 该术语与同类别其它事物的区别(difference).这种句子定义法的句型如下：
Term(术语)=its general class(基本属类)+ how it is different 例如：
A generator is an apparatus which produces electricity.
2.3 扩展式定义：有时一个术语或概念比较复杂或比较重要，用同义词定义或用句子定义还不能够明确解释清楚，或容易与其它同类词混淆时，则有必要使用扩展式定义。扩展式定义的特点是先写被定义的术语，然后再用具体实例证明，并使之与易混的概念区别开来。例如：
Poetry is a branch of literature which explores ideas, emotions, andexperiences in a distinctive form and style. Poetry, sometimes called“verse”, depends greatly on the natural rhythms and sounds of languagefor its special effects. Poetry, even more than prose (all other writings)，depends on precise and suggestive wording. In other words, a poem saysmuch in little space. Poetry differs from prose in obvious way, also. Mostoften the first word of every line begins with a capital letter, even in themiddle of sentence. Poems sometimes contain rhyme, and often they havea particular rhythm, like music.
3 因果法(development by cause and effect)
论述因果关系应首先阐明事物发生的原因， 然后再论述其结果。但在有些情况下可能只说明事情的成因，或者只陈述其结果。在学术研究的各个领域里，因果关系的写作是必不可少的。
We all know that cigarette smoking is a dangerous habit because itcauses health problems. Doctors say it can be a direct cause of cancer ofthe lungs and throats and can also contribute to cancer to other organs.Besides, it can bring about other health problems such as heart lungdiseases…It is clearly identified as one of the chief causes of death inour society.
因果法常用词汇有：
3.1 动词： 引述原因的有：to result from; to be the result of; to be dueto; to be a consequence of…引述结果的有：to lead to; to contribute to; to result in; to be thecause of, cause…
3.2 常用有介词和介词短语有：because of, owing to, on account of.
3.3 常用来表示原因的连词有：because, as, since. For, in that, nowthat, seeing that, considering that,
3.4 常用来表示结果的语言素材有：so that, so…that, such…that,therefore, as a result, consequently, according ly, thus 等。
4 程序法
程序法是段落扩展的一种重要手段。表示程序的段落扩展是按时间顺序展开的。它有两种形式，即过程描述和过程指导。前者用于介绍某种事的发生过程，目的在于向人们提供信息知识;后者来告诉人们怎么做，目的是就某项工作向人们传授实际操作方法。在程序描述中，我们根据事情发生的前后或者遵循程序或步骤，逐步描述。这各种段落扩展法常为科技文章所采用，并且动词常用被动语态。例，
Do you know how paper is made? First, the logs are put in theshredder. Then they are cut into small chips and mixed with water andacid. Next they are heated and crushed to a heavy pulp to be cleaned. Itis also chemically bleached to whiten it. After this, it is passed throughrollers to flatten it. Then, sheets of wet paper are produced. Finally, thewater is removed from the sheets which are pressed dried and refineduntil the finished paper is produced.
这是描述造纸的程序，一道工序接一道工序，否则就生产不出来。本段运用了大量被动语态。这种段落发展———程序描述———常为科技文章所采用。
5 时间顺序法( time order)
时间顺序常用来叙述一个故事，回顾历史事件以及讲解一个过程等。按时间顺序安排组织的段落或文章应该先发生的先说，后发生的后说。所以组织用这种方法的扩展段落时，应注意选用时序信号词，如first, second, third, at first, then finally 等。例，
There are three steps involved in making a woodcut(木刻，木刻画).The first step is to cut a pattern on a flat block of wood. Second, spreadprinter’s ink over the surface of the wood block. Third, press the inkedblock against a sheet of paper. When the ink has bride on the paper, yourwoodcut is finished.
6 空间顺序法(development by space)
按空间关系扩展的段落，它一定依照素材中所提到的位置以及相互关系加以说明。表示空间位置是指事物或人在空间所处的位置排列。如：从上到下，从左到右，由近及远，从外到里等。总之，在描写时，应选择一个合适的起点开始，然后按照一定的顺序描写。使读者能够跟着作者的思路去顺利地理解。表示空间关系(spacial relation) 常用的一些方位词或表方位的词组有：above, across from, also, around, up, under, below, beyond, down, here, inthe distance, nearby, next to, close to, on the left, on the right, oppositeto, on top of, beneath, over, vertical horizontal, parallel to 等， 这类表示上下左右，前后四方的词或词组常用来在表示空间段落的扩展中充当连接纽带。这类文章可大至一个国家，小至一个房间。当然所描述的地方范围越小，就越容易着手写。例如：
My house consists of two floors: the ground floor and the first floor.On the ground floor there’s the dinning-room, sitting-room, the kitchenand the hall. In the hall we keep a stand for hats, coats and umbrellas. Astaircase leads from the hall to the landing on the first floor. On this floorthere are four bedrooms, a bathroom and lavatory. On top of the roof thereare three chimneys. In front of the house we have a small garden, inwhich we grow flowers. At the back of the house there’s a much largergarden with a lawn and some fruit trees. At the side of the house is agarage, where I keep my car. The garden is enclosed by a fence, with agate in it.
当然，段落扩展的方法决不仅仅限于这些内容，而是多种多样的。但是，如能细心领会并掌握了以上所述的十种段落扩展方法，这将对学生的写作起到一定的帮助作用，从而，使学生的写作水平得到稳步提高。