高中英语写作之段落设计
一般说来，一个段落由三部分组成：主题句，扩展句和结论句。主题句提出的论述的主题， 扩展句利用必要的细节对主题加以论证说明，结论句总结全文，在论证的基础上得出结论。这三者是段落的必要成分，他们相辅相成，构成一个完整的段落。有些段落还有过渡句，它起到段与段之间的顺利过渡。下面具体说明：
1.主题句
1）主题句的位置：请找出段落的主题句
Smoking is harmful to your health. Experiment show that smoking can cause cancer. Besides the most serious disease cancer， smoking can also cause other health problems. For example， it gives one a “smoker’s cough”. Finally， studies have shown it is easy for smokers to catch colds. Whether you get an unimportant cold or the terrible killer， cancer， smoking is harmful. Is it worth it？
2）写好主题句， 有两条原则
①主题句要明确， 句中须有一个词，词组，或从句让读者一目了然本段的确切主题， 明确本段的重点或观点。
②主题句要概括， 它陈述你要说明的重点和观点，句中必须包含有可扩展主题的词，词组或从句。他应该是你将进一步表明你的态度和看法的概括。同时， 主题句有利于控制作者本人的主题的扩展。
练习：下面一段没有主题句，请根据全段内容拟定一个主题句。
___________________________. For example teachers live by selling knowledge， philosophers by selling wisdom and priests by selling spiritual comfort. Though it may be possible to measure the value of material goods in terms of money， it is very difficult to calculate the true value of services which people perform for us. The conditions of society are such that sills have to be paid for in the same way that goods are paid for at shop. Everyone has something to sell.
2.扩展句
扩展句的作用是丰富，支持，扩展主题句的内涵。扩展句的表达形式是多种多样的， 可以按时间或空间顺序，从整体到局部从局部到整体的方法叙述，描写，说明或议论，也可用比较，对比，比喻， 推导，归纳，演绎的手段来展现。
在作文中， 我们常会谈到首先， 其次， 然后， 该如何表达？
1） first， second， third， last
2） the first， the second， the third， the last
3） to begin with， then， furthermore， finally
练习：根据所给的主题句和提示， 写好段落的扩展句。
主题句： How excited we were when we learned that we were going to have a spring hour.
①after―discussion―agree―climb―out of the city
②we―often pass by mountain―the first time―think of―climb it
③set out―early―morning
④about―an hour―begin―tired―still a long way―go
⑤short break―go on―climb
⑥lunch time―get to the top―mountain
⑦our beautiful city―below us―happy―very tired
结尾句：It proves that many things are just like climbing a mountain； they look attractive， but they are not easy to do.
参考答案：After a heated discussion we agreed to climb the mountain outside the city. We had passed by the mountain when we were taking a bus out of the city， but it was the first time we had thought of climbing it. We started early in the morning. About an hour later， we began to feel tired， but there was still a long way to go. We took a short break and then went on climbing. Not until lunch time did we get to the top of the mountain. At sight of our beautiful city below us， we felt happy though we were tired out.
3.结论句
结论句并非必不可少， 但它能起到以下的作用：（1）表示段落的结束。（2）总结要点，与主题句相呼应。（3）供读者就本段落的主要内容和见解有个深刻的印象或进行思考。
推荐几种常用结论句：
感叹句 1.（主题句：Life is limited， but knowledge is boundless.）
结尾句： How important it is to read good books！
疑问句2.（主题句：Books are full of knowledge and wisdom.）
结尾句：Why shouldn’t we read more books to search more and use them to develop our splendid future？
比喻 3.（主题句：When I was a little girl， I lived with my grandparents in a faraway village.）
结尾句： Time was gone with the wind. But my childhood is like amber（琥珀）， glittering in my life.
总之，英语书面表达的训练是综合能力的训练之一。大量的多种训练要贯穿于英语教学的始终，因为英语的听说读写是相互影响、相互作用的有机统一体。平时要鼓励和指导学生多读多练，坚持不懈，以至达到“下笔如有神”的境界。
