有关说明文写作指导

　　说明文是以说明为主要表达方式，介绍事物的形状、构造、性质、变化、类别、状态、功能、成因、结果等特征的文章。它是一种应用性很强的文体，说明的目的.是让读者有所知，给读者提供知识，使之了解客观世界，掌握解决问题的方法。说明文的基本特点就是具有知识性、科学性、应用性、解说性和条理性。常见的说明文有：解说词、说明书、书文简介、内容提要、科普小品、生产工艺、操作规程和景物介绍等，常见说明方法有：定义、注释、举例、分类、比较、引用、比喻、描述、数字分析和综合等。说明文的时态常用一般现在时，语态常用被动语态，有时用虚拟语气。对中学生而言，说明文的出题形式为文字提示或图表、图示，文体则可见于短文、书信、便条、日记等。写说明文必须注意事实正确，表达清晰，条理清楚，层次分明，语言简练和用词准确。
　　说明文范文赏析
　　说明文是对事情的发生、发展、结果、特征、性质、状态、功能等进行解释、介绍、阐述的一种文体。这类文章的目的和性质是客观地介绍、解释事物，使读者获得知识和信息，并不需要发表主张、做出证明。一般说来，知识简介，商品介绍，旅游指南，科技读物，工作总结，实验报告，教材辅导等均属说明文之列。
　　写说明文，可以按时间、空间、结构、逻辑顺序来写，也可以采取举例、比较、对比、分类、分析、说明、叙述等方法。
　　1.分类
　　分类是人类认识客观世界的重要手段之一，也是描写事物、解释观点最有效的方式之一。通过将一事物分类，可使复杂事物变得清晰明了，便于作者阐述自己的观点。
　　分类段落的各类排列要条理，可采用从主要到次要，从次要到主要，从多到少或从少到多等方式排列，亦可平行排列。如：
　　1) As far as political views are concerned, people fall into three categories. First are the conservative people. Conservatives are opposed to sudden or great changes. Second are the liberal people.These people are in favor of progress and reform. But their opinions often seem to idealistic. The third type is the moderate people. The moderates keep everything within reasonable limits. They are more practical in this hard world. In my opinion, most people seem to belong to this group.
　　2.比较对照
　　比较对照有两种，一是逐点比较，二是整块比较，即AB交错或先A后B：
　　1)逐点比较：多数人认为这种AB交错的方式可以避免行文的单调沉闷，对比的效果更鲜明突出。如：
　　There are basic differences between large and small enterprises. In a small enterprise, you operated mainly through personal contacts. In a large enterprise, you have established ＂policies＂ , ＂channels＂ of organization, and fairly strict procedure. In the small enterprise you have immediate effectiveness in a very small area. You can see the effect of your work and of your decisions ground. In the large organization you are normally taught one thing thoroughly. In the small one the danger is of becoming a Jack-of-all-trades-but-master-of-none. In the large it is of becoming the man who knows more and more about less and less.
　　2) 整块比较
　　It is easy to be a winner. A winner can show his joy publicly. He can laugh and sing and dance and celebrate his victory. People love to be with winners. Winners are never lonely. Unlike winners, losers are the lonely ones of the world. It is difficult to face defeat with dignity. Losers can not show their disappointment publicly. They can not cry or grieve about their defeat. They may suffer privately, but they must be composed in public. They have nothing to celebrate and no one to share their sadness.