（第一节）段落的建构过程
一、限题（Narrowing Down the Topic）
英文段落写作过程大致可分为以下几步：限题（narrowing down the topic）、写主题句(writing the topic sentence)、拓展(coming up new ideas)、组织思路(organizing ideas)、规划段落提纲 (arranging ideas in plan )、最后初稿写作和修改(writing and revising the paragraph)。
在现实的写作中，老师或试卷给你的是一个很泛的主题（too broad topic）， 如TV，My Favorite Place， My Classmate， 大多学生面对这种题目，不加考虑，把脑子里想到的一股脑地写下，结果文章泛泛而谈，甚至自己都不知文章写的究竟是什么，因此，限题是非常必要的。以My favorite place为例，看到这一题目，你可能会想到的地方有许多，如中学、小咖啡店、公交车站、图书阅览室等。（相反，有时一看题目，脑中一片空白，即使如此仍然有许多方法，如通过提问“何处是我最喜欢的地方”或列表等打开思路，搜寻丰富的可写内容。）比如，你认为Los Angels 是你最喜欢的地方，你就可以围绕Los Angels is My Favorite Place限制写作内容。(限制可能不太雅，但对初学写作者，该词较合适些。)
Broad topicsNarrowed topics
Food Why I Like Daniang Dumplings
Pollution control An Effective Way to Control Air Pollution
Examination Two Kinds of Tests
Childhood A Bitter Experience in My Childhood
Selfeducation The Importance of Selfeducation
Stamp collecting The Advantages of Stamp Collecting
Money The Right Use of Money
Traveling The Disadvantages of Traveling individuality
如果不把内容限制到一定范围，就不知如何写、写什么，限定后的主题才有可能写成一段有价值的文章。段落的主要内容（八个方面）选定后，下一步就是主题句的写作。
二、写主题句 (Writing Topic Sentence)
主题句就是告诉读者本段写了什么，主题句必须是能表达完整思想的句子。短语、句子片段（Sentence Fragment）是不可能做主题句的。
如：Sentence Fragment：The expense of maintaining a car；
Topic Sentence： Maintaining a car is expensive.
主题句的内容应该具体化，越具体对段落的写作越好，如主题句为：“ the paragraph will discuss Mary"s little bookstore.” 此句表述内容太泛，读者也无从理解作者对要写对象的态度。相比之下，“Mary"s little bookstore is my favorite store in the town”好些，它不仅表明了写作对象“Mary"s little bookstore”，而且表明了作者的态度“favorite”。前面，我们提到“My favorite place”假定是“Los Angels”。主题句可表述为“Los Angels is a pleasant place to live”。同时也可以把选定的内容写成主题句形式。
Narrowed topic： Why I Like Daniang Dumplings
Topic sentence： I like Daniang dumplings for many reasons.
Narrowed topic： An Effective Way to Control Air Pollution
Topic sentence： An effective way to reduce the air pollution is to limit the number of private cars.
Narrowed topic： Two Kinds of Tests
Topic sentence： There are mainly two kinds of tests in modern exams.
Narrowed topic： A Bitter Experience in My Childhood
Topic sentence： I can"t forget a bitter experience in my childhood.
Narrowed topic： The Importance of Selfeducation
Topic sentence： Selfeducation is important to students.
Narrowed topic： The Advantages of Stamp Collecting
Topic sentence： There are several advantages to collect stamps.
Narrowed topic： The Right Use of Money
Topic sentence： One should use his money properly.
Narrowed topic： The Disadvantages of Traveling individuality
Topic sentence： Traveling individually has several disadvantages.
我们来分析有关主题句的两个写作实例， 看看中国人对主题句的理解和西方有何不同，你如何看段落主题句？段落主题句对你的英语写作有何启发？
In this world， we should think more of other people than of ourselves. By doing so， our world will be full of happiness. This， of course， is my personal view. But it is a lesson I have drawn from one of my own experience. So now， I would like to share that experience with you， my dear reader.
这是一名中国大学生的作文Applause on the Bus中的开头。然而美国编者认为：This is essentially a solid essay. The writer uses an anecdote to make a point... Now we just need to give it a good， strong topic sentence using the writer"s own ideas to form it. 她给这个开头段拟了下面的主题句：
A little girl taught me an important lesson about the importance of thinking more of other people than of ourselves. One day I took a very crowded bus to school...
在另外一篇作文Part of My Childhood中，作者开头是这样写的：
In my childhood， there were so many things that were worth calling to mind. Some made me happy， some made me excited， and some made me sad. But among them was an unforgettable thing， when I think of it， my good friend Tong Tong will occur to me.
美国编者认为：
This is a moving story about friends who have quarreled. It needs a good topic sentence to bring the reader into the feelings and message the writer wants to convey.
这位美国编者提供了这样的开头：
One of the most unforgettable experiences of my childhood involves my good friend Tong Tong. It happened when I was eight years old.....
主题句的位置：主题句可在段落之首、之末或中间，但中国人较习惯把主题句放在段落之首和末尾，尤其段落第一句。当然有的文章无段落主题句。下面我们分别鉴赏这几种实例。
1. 主题句在段首
Jane and Karen have many things in common. To begin with， both girls have the same background. Jane was born and raised in the West， and so was Karen. Next， both girls are interested in the same kinds of subjects in school. Jane likes French， history， and English. In the same way， Karen likes Spanish， history and English. Furthermore， both girls want to be teachers. Jane plans to become an elementary school teacher. But Karen wants to be a high school teacher. As you can see， the two girls are almost like twins.
Even when we are very careful in the things we do each day， the risk of loss and injury is always with us. Starting the day with a shower， we risk slipping and falling through the glass door. Riding to work， we risk collision. While we are away from our homes， the risk of fire and burglary is greater. Going to school， our children risk being injured. We also lose through unintentional actions of our own that might injure others. Such events may occur regardless of how careful we may try to be， and they can cost us a lot of money. Rather than taking the chance of being wiped out financially， we transfer some or our risks to others， we buy insurance.
Eating lunch is one of my favorite pastimes. Because lunch comes in the middle of the day， it gives me a welcome break from studying. At school， lunch means thirty minutes out of class and a chance to rest after the morning"s work. While eating， I can plan what I"m going to do in the afternoon. And besides offering a pleasant break in the day， lunch is always a good meal.
2. 主题句在段落中间