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 1 描写事物 describe something 2 争论某事 argue about something 3 或对某事提出疑问 question something 4 要求什么 demand something 5 给事物下定义 define something 6 驳斥某观点 reject something 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 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 示范段落分析 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 direct 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 从以上提纲可见 主题句提出了一个问题 What kind of health problems does cigarette smoking cause 随后的两个推展句回答了这个问题 结论句总结了推展句 并再一次强调主题句 Exercise 1 The need for wildlife protection is greater now than ever before About a thousand species of animals are in danger of extinction and the rate at which they are being destroyed has increased With mammals for instance the rate of extinction is now about one species every year from A D 1 to 1800 the rate was about one species every fifty years Everywhere men are trying o solve the problem of preserving wildlife while caring at the same time for the world s growing population Topic Sentence Details Concluding Sentence Topic Sentence The need for wildlife protection is greater now than ever before Details 1 About a thousand species of animals are in danger of extinction and the rate at which they are being destroyed has increased 2 With mammals for instance the rate of extinction is now about one species every year from A D 1 to 1800 the rate was about one species every fifty years Concluding Sentence Everywhere men are trying o solve the problem of preserving wildlife while caring at the same time for the world s growing population 2 The Americans and the British not only speak the same language but also share a large number of social customs For example in both America and England people shake hands when they meet each other for the first time Also most English men will open a door for a woman or offer their seat to a woman and so will most Americans Promptness is important both in England and in America That is if a dinner invitation is for 7 o clock the dinner guest either arrives close to that time or calls up to explain his delay 1 Topic sentence 2 Details 3 Concluding sentence Topic Sentence The Americans and the British not only speak the same language but also share a large number of social customs Details 1 For example in both America and England people shake hands when they meet each other for the first time 2 Also most English men will open a door for a woman or offer their seat to a woman and so will most Americans 3 Promptness is important both in England and in America That is if a dinner invitation is for 7 o clock the dinner guest either arrives close to that time or calls up to explain his delay Concluding Sentence 3 Birds use many different materials to build nests Some birds use bits of grass The tailor bird of Africa and India uses grass to sew leaves together Other birds find twigs and pebbles useful 1 Topic sentence 2 Details 3 Concluding sentence Topic Sentence Birds use many different materials to build nests Details 1 Some birds use bits of grass The tailor bird of Africa and India uses grass to sew leaves together 2 Other birds find twigs and pebbles useful 3 Concluding Sentence