2020年大学英语四级写作题型及作文范文：说明文.docVIP

2020 年大学英语四级写作题型及作文范文：说明文 说明文是以说明为主要表达方式用来说明事物，阐明事理的一种 文体。它通过揭示概念来说明事物的特征、本质及其规律性，给人准 确的科学知识或准确思想。一般可分为实体事物说明和抽象事物说明 两大类，词典、教材、论文、实验报告、产品说明书、广告、解说词 及科学小品等都属于说明文。 按写作方法 , 英语说明文主要分为下面六种类型： 1. 例证法 这是用具体例子来说明人或事物的特征、本质及其规律的方法 , 所 用例子必须有代表性、典型性 , 能体现人或事物的本质特征。这是用特 殊来说明一般的方法。通常在主题句后 , 用 For example 或 For instance 等短语引导出具体的例子。例如： Our life today depends very much on energy. For example, machines have made our life easier than it used to be. The machines use energy, and energy is needed for heating, lighting, communications, carrying goods-everything. Factories use a great deal of energy to make the things that we use and buy and sell. 这段主要是讲能源问题。第一句为主题句 , 概括地说出 我们当前 的生活很大水准上依赖能源 。接着用举例的方法从三方面说明能源的 作用。 2. 定义法 下定义就是给说明对象一个明确概念。这是科学而严密的说明方 法。它既能揭示事物的本质特征 , 勾勒其大概 , 描绘其轮廓 , 同时也能确 定事物的范围和界限。下定义是多方面的 , 能够给人、事物、思想等下 定义。例如： An ideal teacher must have the following characteristics. He should know his subject, but he can make mistakes if he is willing to learn. His personality is as important as his scholarship. An ideal teacher must be enthusiastic. He should be a bit of an actor and he shouldnt be afraid to show his feelings and express his likes and dislikes. An ideal teacher is one who grows, learns, and improves himself along with his students. 本段的展开是通过对 一个模范教师 下定义的方法 , 关键词ideal teacher 在文中多次重复 , 能加深读者的印象。 3. 分类法 分类法是对同属不同类或同类而不同种的人或事物 , 根据不同性质 实行分门别类地说明的方法。分类是人类理解客观世界的重要手段之 一。分类必须遵守分类规则 , 使分类对象具有统一属性 , 依据同一分类 标准, 并使分类的子项相互排斥 , 不互相包蕴。例如： 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 too idealistic. Third are 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. 本段把人按政治观点分为三类：保守派 (conservative people) 、 自由派(liberal people) 和温和派(mo