第一单元 段落简介

1．1段落

段落是构成文章的一组句子。段落必须表达完整的意思：或描写事物（describe
something），或争论某事（argue
about something），或对某事提出疑问（question
something），或要求什么（demand
something），或给事物下定义（define
something），或驳斥某观点（reject
something）。

1．2典型段落的构成

一个典型的段落通常由三部分组成：（1）主题句（the topic sentence）；（2）说明或支持主题的推展句（ supporting sentences）；（3）结论句（the
concluding sentence）（有些段落没有该部分）。

示范段落1-1

We all know that cigarette smoking is a dangerous habit because it
causes health problems． Doctors say it can be a direct cause of cancer of the lungs and
throat and can also contribute to cancer of other organs． In addition， it can bring about other health
problems such as heart and lung diseases． It is clearly identified as one of the chief causes of death in our
society．

1．3示范段落分析

这是一个典型的段落，可概括提纲如下：

主题句： We all know that cigarette
smoking is a dangerous habit，because it causes health problems．

推展句： 1． Doctors say it can be a direc cause of cancer of the lungs and
throat and can also contribute to cancer of other organs．

2． It can bring
about other health problems such as heart and lung diseases．

结论句： It is clearly identified as one
of the chief causes of death in our society．