Ⅲ.段落的展开
在确定了各段的主题之后，怎样展开段落成为了写作成败的关键。展开段落的方式各式各样，但主要有以下几种：
1.列举法
列举法是指通过列举一系列的论据对主题句中的论点进行广泛、全面的陈述或解释，在使用列举法时，我们要注意：一、所列举的各个要点按照递增或递减的顺序进行有层次的排列。二、所列举的要点应该服务于一个中心思想。各要点必须相互独立、相互区别。如：
Yesterday was one of those awful days for me when everything I did went wrong. First， I didn't hear my alarm clock and arrived late for work. Then， I didn't read my diary properly and forgot to get to an important meeting with my boss.During the coffee break， I dropped my coffee cup and spoilt my newskirt. At lunch time， I left my purse on a bus and lost all the money that was in it. After lunch， my bosswas angry because I hadn't gone to the meeting. Then I didn't notice a sign on a door that said “Wet Paint”and so I spoilt my jacket too. When I got home I couldn't get into my flat because I had left my key in my office. So I broke a windowto get in and cut my hand.
本段的主题句是第一句“Yesterday was one of those awful days for me when everything I didwent wrong.”之后，作者按照时间顺序列举一系列的事实来阐述昨天发生的一切来解释为什么昨天对作者来说是可怕的一天。在本段中，作者所用的一些连接手段：first， then， during the coffee break， at lunch time， after lunch，then， when I got home.
常用于列举法的过渡性词语：
First， second， third， etc. ， in the first place， in the second place， first of all， first and foremost， to begin with， to start with，for one thing， for another， also， besides， furthermore， moreover， in addition， what is more， above all， next， beyond that， initially，eventually， last but not least...
2.举例法
在主题句中简要、概括地说明一个段落的主题思想之后，可以用具体的、生动的事例来支撑论证主题，向目标读者展示并使他们具体感受主题句中尚未展开的内容和细节，严格地讲，举例法也是列举法的一种，它们的区别在于：列举法侧重罗列事实，所列事实力求全面；而举例法则侧重通过举出典型事例来解释作者观点，且事例可多可少。如：
There are many different forms of exercises to suit different tastes. For example， those who enjoy competitive sports may take up ball games. For another example， if they prefer to exercise alone， they can have a run or take a walk in the morning or in the evening. Besides， people can go swimming in summer and go skating in winter. In short， no matter what their interests are， people can always find more than one sports that are suitable to them.
本段采用了三个事例来说明主题句中的关键词组different forms of exercises，这三个例子分别由连接词for example， for another example和besides引出，最后由结尾句总结全段内容。
常用于举例法的过渡性词语：for example， for instance， as an example， as an illustration， such as/such， a case in point is， to illustrate， in particular， specifically， say， next， namely， that is，like， take ... as an example， etc.
3.叙述法
叙述法发展段落主要是按照事物本身的时间或空间的排列顺序，通过对一些特有过渡连接词的使用，有层次分步骤地表达主题句的一种写作手段。用这种方法展开段落，作者能够清楚连贯地交代事物的本末，从而可以使读者可以清晰、完整地理解文章的含义。如：
In the flat opposite， a woman heard the noise outside. When she looked out through the window， she discovered that her neighbor was threatened by someone. She immediately called the police station. In answer to the call， a patrol police car arrived at the scene of the crime quickly. Three policemen went inside the flat at once， and others guarded outside the building to prevent anyone from escaping.
这段是按照事物发展的先后顺序，叙述从发现案情、报警、到警察赶到、包围现场的过程。全文脉络清晰，叙述的层次感强，结构紧凑。
常用于叙述法的过渡性词语：first， an the beginning， to start with，after that， later， then， afterwards， in the end，finally等。
4.比较对照法
比较对照法由比较和对照两部分组成，但两者往往一起用以阐述两者或者更多事物间的异同，常用于说明文和议论文写作。比较描述的是所比对象的相同、类似点，而对照则强调所描述对象之间的不同，甚至相反之处。
常用的比较对照的结构模式有两种，即整块比较法（block comparison and contrast）和逐点比较法（alternating comparison） ，在整块比较法中先集中描述A，再集中描述B。其模式为：Al， A2，A3…… B1， B2， B3……如：
Computers have both favorable and unfavorable aspects.First， computers can calculate. They can make work more efficient for they have a high speed of calculation. Besides，people can communicate with each other by E-mail， which costs people less money and less time. Most important of all ， computers create wide communication around the world. People can communicate with each other via the Internet. They can make friends all over theworld. But every coin has two sides. The negative aspects are also apparent. To begin with， since computers can do a lot of work for us， such as calculation ， we may rely too much on them and become lazier and lazier. To make matters worse， although it is convenient for people to communicate with each other by E-mail， the original warm relationship may become cold， for people will have fewer opportunities to talk to each other face to face. Worst of all， computers can spread viruses caused by electronic hackers resulting in a lot of important information being lost.
逐点比较法是A、B双方同时逐点描述，其模式为：Al B1； A2 B2； A3 B3…如：
A proverb says， “Like father， like son. ” But the proverb doesn't seem to fit my grandfather and my father because they have more differences than similarities. First， my grandfather is introverted， while my father is extroverted. We can easily read what is on my father's mind， but it is hard to find out what my grandfather is thinking about. Next， my grandfather is always indifferent to children. He seldom talks with children and the children are somewhat afraid of him. In contrast， my father is very warm-hearted to children. He likes to talk with them ， so the children in my family all like him. Finally， my grandfather is obstinate. Once he has made a decision ， he never changes it.However， my father， even after he has made a decision， will ask others for opinions. If he thinks the opinions are reasonable， he might change his mind. Although my grandfather and my father resemble each other very much in appearance， they differ in character， thinking and behavior.
常用于表示比较的过渡性词语：similarly， likewise， correspondingly，in a similar way， in the same way， too， like， resemble， similar to，equal to， equally， important， both... and... ， the same as.
常用于表示对照的过渡性词语：on the one hand， on the other hand， on the contrary， in/by contrast， in contrast to， in sharp contrast， conversely， otherwise， however， nevertheless， but ， yet，（ al）though， even though， whereas/while， it is true... but， instead，unlike， rather than， in spite of， contrast with， differ（ ent） from，contrary to。
5.分类法
在阐述某一概念的段落中，常用分类法。通过对概念中所包括的事物进行分门别类，分别加以叙述，使读者有更为清晰的认识。所谓“分类”就是根据人物和事物的特征将他们/它们分别归入各自不同的范畴。在写这一类段落时，一定要抓住各个类别的典型特征，不要异类相串，混淆起来。如：
Ever since humans have lived on the earth ， they have made use of various forms of communication. Generally， this expression of thoughts and feelings has been in the form of oral speech. When there is a language barrier， communication is accomplished through sign language in which motions stand for letters， words and ideas. Tourists and the people unable to hear or speak have to resort to this form of expression. Many of these symbols of whole words are very vivid and exact and can be used internationally； spelling， however， cannot. Body language transmits ideas or thoughts by certain actions ， either intentionally or unintentionally. A nod signifies approval， while shaking the head indicates a negative reaction. Other forms of nonlinguistic language can be found in signal flags， Morse code（莫尔斯电码）and picture signs.
在该段中为了说明主题句中的“various forms of communication”，作者将其分为oral speech， sign language， body language及other forms of nonlinguistic language，并逐一加以阐述。
采用这种方法的段落并没有标志突出的连接词，所述各项均为平行并列关系，所以没有明显的主次之分。
常用于表示分类的过渡性词语：动词：sort （into） ， divide（into） ， classify， group， fall into等。名词：sorts， classes， groups，categories，types， kinds ，aspects等。
6.因果法
因果分析是常用的拓展段落的方法之一，一定要注意推理的逻辑性，因果关系必须表达清楚，不能因果混淆，更不能因果倒置，要避免牵强附会和循环论证。一个原因可能造成一个或多个结果，也可能在一大段文章中涉及一连串因果关系。一个结果也可能由多种原因所引起，通常先写结果，后写多种原因；但也可先写原因后写结果。另外，如果要强调原因或结果，可用倒装或强调句型加以突出。如：
The role ofwomen in today's society is changing. One reason is that women have begun to assert themselves as independent people through the women's movement. Also， women are aware of the alternatives to staying at home. Another reason is that increasing numbers of women who enter new fields and interests serve as role models for other women. Moreover， men are becoming more conscious of the abilities of women and have begun to view their independence positively.
本段中，主题句提出了一种社会现象，推展句则对产生这种现象的原因作出各种解释。
常用于因果关系的过渡性词语：because， as， since， for， owing to，because of，due to，on account of，as a result of，for the reason，result from， thus， so， therefore， accordingly， consequently， for this reason， on that account， as a result， as a consequence， it follows that... ， result in， contribute to等。
7.定义法
有时候为了避免混淆或误解，我们必须对一个词、一条术语或谚语、一个概念通过下定义加以说明、解释。通常有三种方法下定定义：给出同义词；用一个带有定语从句的复合句或用一整段文章；而以第三种方法最为常用。在科普文章的写作中，定义法是必不可少的。通过下定义，可以使读者对该事物有一个更直接的认识。如：
Automation refers to the introduction of electronic control and automation operation of productive machinery. It reduces the human factors， mental and physical， in production， and is designed to make possible the manufacture of more goods with fewer workers. The development of automationin American industry has been called the “Second Industrial Revolution”.
这一段文字使我们了解了“automation”和“Second Industrial Revolution”两个概念，分别由“refers to”和“been called”引出。
常用于定义法的词语：refer to，mean，call等。
8.重复法
句子的一部分反复出现在段落中，这就是重复法。它往往造成一种步步紧逼的气氛，使文章结构紧凑，有感染力。如：
Since that time， which is far enough away from now， I have often thought that few people know what secrecy there is in the young ， under terror. I was in mortal terror of the young man who wanted my heart and liver； I was in mortal terror of my interlocutor（对话者）with the iron leg； I was in mortal terror of myself， from whom an awful promise had been extracted.
该段中反复应用了I was in mortal terror of…我经常处于恐怖之中……
以上是我们结合具体文章讨论了展开段落的几种方法。在实际写作中，我们往往不必拘泥于一种写作方法，而是将若干方法穿插在一起，使文章有声有色。