主题句扩展句和结尾句--四六级作文好点子

　　通常段落由二至三部分组成,即主题句，扩展句 和结尾句组成。主题句是段落的核心，它表明作者的观点和态度，同时反映段落的中心思想。主题句的特点是：一是具有明确的观点；二是具有一定的概括性。

    记住段落的中心思想应该是一个，要清楚地把它表达出来，尽量不要出现语言错误。如： Advertisement is an important link between producers and consumers today.\The library supplies people with knowledge of all kinds.\Nowadays ,the computer has found wide applications in many fields.以上句子都具备了主题句的特点，因为所有这些句子都可以用其它句子来解释，描述，分析等即扩展句———主要围绕主题句进行叙述。说明或论述，它是主题句发展成短落的主要组成部分。

    请看下面的段落： Nowadays ,the computer has found wide applications in many areas .It is used not only in caculations,but also in an engineering project,designing ,language learning,etc.In today's society ,computers can be seen working for us almost everywhere ,in shops ,banks ,post offices ,schools ,hospitals ,and so on .Computers have even entered most families .Children can learn various subjects on computers ,and parents can enjoy some entertainment from the computer,too.

    同学们可以看出本段的扩展句是：It is used not only ----后的四个句子 ，这些句子都紧紧围绕主题句展开，叙述计算机在各个领域的应用，同时它们在语法和语义上是完整和连贯的，扣住了主题句的中心思想。

    结尾句是指用一句话将某段落的内容进行归纳总结，引发读者对段落的进一步认识，请看下面段落： There are many problems with advertisements .Sometimes ,people consider them as a bad thing because many of the goods sound .Some advertisements are rather confusing ,and often deceive consumers into buying goods of poor quaity.The solutions to these problems is that a necessary law should be worked out .Otherwise some advertisements will be harmful to the society. 该段的结尾句是：The solution ----harmful to the society.最后一句说出了解决的方式及不加以解决会产生的不良后果。但要注意的是段落结尾句需要简明扼要，并符合主题句的主旨，不过不能简单的重复。

    以上是段落的基本写作套路和方法，请同学们根据上述方法将下列主题句扩写成60字左右的段落：
    1.Almost every big city in China has a serious traffic problem.
    2.Intoday's society,everyone needs friendships .
    3.Smoking is harmful to the health of people .
    最后祝愿同学们作文轻松考出好成绩。