Topic
段落是文章的基础，由一些句子组成，发展而成一个中心思想，换句话说，段落是作者陈述一个主题“topic”，所以文章的布局结构往往可从段落中反映出来。当你看到一个主题时，要先缩窄 (narrow down) 所写的题目内容，例如：
Drugs→Effects of Smoking Drugs→Effects on Health→Effects on Memory
这段落是讨论吸毒的影响,引申题目至“记忆力衰退”，这样你便可专注此项来写这段落了。现在，试就此题目收窄所写的内容：
Drugs→Reasons People Smoke It→......→......→......
The Topic Sentence 主题句:
撰写段落时，首先须要决定你的写作目的，而当你拟定了主意（idea）后，便可以开始写这段落的主题句。
写主题句的要点包括：
1) 主题句共分两部分：Topic + Controlling Idea 例如：
2) 主题句不能太含糊，范围太大，令人不明白你的重点；若主题句太细致，则很难再去阐述或讨论下去，所以要在限定范围内展开你的话题。
例如：Exercise is good for you. (too general)
Aerobic exercise is good for your health.(suitable)
Driving a car can behazardous. (too general)
Drunk driving is hazardous. (suitable)
3) 主题句可放在段落之首，中间或是最后，也可隐藏于句中，视乎你想怎样表达。不过，很多时候，在开首写出主题句的方式，较容易引起读者的注意，同时，便于环绕中心主题铺陈开展下文，引导读者了解段落大意。
4) 主题句必须表达你对该题目的独特见解，所持态度，或是理据所在，才能吸引读者继续看下去。
Exercise:
Choose one of the following topics and brainstorm the topic. After writing everything that comes to your mind on the topic, sort through the list and choose an idea that interests you. Write a topic sentence that has acontrolling idea. If necessary, narrow down the topic further.
Cloze Exercise (2)
Please complete the following cloze exercise:
(word list: 40 words)
Some people think they have an answer to the troubles of automobile crowding and dirty air in large cities. Their answer is the bicycle.
In a great many ______, hundreds of people ride ______ to work every day. ______New York City, some bicycle riders have even formed______ group called Bike for ______Better City.They claim______ if more people rode ______ to work, there would be fewer automobiles in the ______ section of the city, ______ therefore less dirty air______car engines.
For several ______ this group has been ______ to get the city ______ to help bicycle riders.For ______, they want the ______ to draw special lanes--- ______ bicycles only --- on some ______ the main streets, because ______ bicycle riders must use ______ same lanes as cars, ______ are accidents. Bike for ______BetterCityfeels that______ there were special lanes, ______people would use bikes.
______ no bicycle lanes have ______ drawn. Not everyonethinks ______ are a good idea. ______ drivers do not like the ______ --- they say it will ______ traffic. Some store owners on the main streets do not ______ the idea --- they say ______ if there is less ______ they will have less ______. And most people live ______far from downtown to travel by bike.
The city ______ has not yet decided ______ to do. It wants ______ keep everyone happy. On Sundays Central Park --- the largest area of open ground in ______York--- is closed to______, and the roads may be used by bicycles only. But Bike for a Better City says this is not enough and keeps______to get bicycle lanes downtown.