第五节类比（comparison）和对比（contrast）

类比和对比是写作中常用的方法。我们通常对比生活的过去和现在,对比中西方文化，广告的好处与弊端，等等。通过类比和对比，我们往往可以对事物有一个更加明了的认识。
严格地说，类比用于指出同一范畴的事物之间或者几个人之间的相似之处，而对比则用于指出他们之间的不同之处。但实际上，类比和对比常常同时使用，原因是人们在议论两个人或事物时，往往既提出二者的相同之处，又注意到他（它）们之间的差异所在。
可通过两种不同的做法，用类比和对比的方法展开段落。第一种称为整体类比（subject-by-subject comparison）或整体对比法（subject-by-subject contrast），即在阐述完一件事物的特点之后，再摆出与之相比的另一件事物的全部特点。需要注意的是，进行类比或对比的两件事物的方面应一致，顺序应相同，否则就会相互脱离不成对比。第二种作法称为交替类比（point-by-point comparison）或交替对比（point-by-point contrast），即逐条比较或对比两个人或两种事物的特点。请看下面的例子：
当我们比较上中学和上大学有何不同时，我们可以采用交替类比（point-by-point comparison）或交替对比（point-by-point contrast）法。
  There are many differences between middle school and the college. First, in middle school, we have to listen to what the teacher says in class, to understand the content of the text. But in college, we must study by ourselves before class. If not, we couldn't follow the teacher. Second, there are lots of rules in middle school. For example, we should wear the uniform, the girls must have their hair cut short, and we are not allowed to make boy- or girlfriends. However, in college, we have more freedom. We can wear the clothes we like. And the girls could have long beautiful hair. We are also free to make boy or girlfriends. The third, in the middle school, we must study first. That means we could do nothing but study. In contrast, we have to do everything by ourselves in college. That means we must plan our time carefully. There are also other differences between our school life and our college life. We have to learn to adapt ourselves to college life.?

再如当我们相比较体育运动所带来好处和副作用时，我们可采取整体类比（subject-by-subject comparison）或整体对比法（subject-by-subject contrast），题目："Positive and Negative Aspects of Sports"提纲：
a. 体育运动的好处
b. 体育运动可能带来的副作用
c. 我参加体育活动的体会
Sports do us good in many respects . It goes without saying that taking exercises can build up our physical strength. In collective sports like basketball, volleyball, or football, we will learn the importance of cooperation. While taking part in sports game, we will try our best to win and arouse ourselves the competitive spirit. Sports can also help us relax after a period of exhausting work. However, as the saying goes, "there are two sides to everything", and sports is without exception. We may hurt other players or ourselves if we are not careful enough when participating in sports activities. What's more, excessive or severe training can do harm to our health.
My participation in sports tells me that sports can make us healthy both physically and psychologically. It is also a good way for people to know each other and can promote friendship between people. So long as we are carefully enough, sports can do us nothing but good.
 
通过以上两个例子，我们可以看出，交替类比（point-by-point comparison）或交替对比（point-by-point contrast）法的格式是：A 1 ---- B1；A2 --- B2 ；A3 --- B3
整体类比（subject-by-subject comparison）或整体对比法（subject-by-subject contrast）格式是： A 1，2，3 ---- B1，2， 3。
交替类比（对比）法用于集中讨论两种事物的几个特点，先指出一种事物的一个特点，接着同另一种事物的相应的特点进行比较。这一方法适用于讨论内涵比较简单，特点比较突出的事物。当我们想深入地讨论两种事物的相似的特点而这些相似特点的内涵较复杂，需要详细解释时，可以先详尽阐述一事或一人的各种特点然后再同相比者进行全面的比较。

第六节 分类展开

分类就是根据事物的特点分别归类。我们对各种人或事物进行分类，如树木，河流，城市，公司，大学生等等。比如我们给河流的分类可以按他们的宽度、长度和深度的相近和差别分类，比如我们给河流的分类可按它们的大小、产地、颜色、价格或质量分门别类。
使用分类方法展开段落的关键在于把握好类别的对应性，例如，我们可把各种体育活动分成田径、游泳、球类、体操等几大类，但是如果把它们分成跳高、球类、跑步、体操和自由泳等几类，我们就破坏了事物类别的平行性。因为，在这个例子里，球类和体操本身是两大类别，而跳高、跑步、自由泳是别的大类别里的具体项目，彼此不能混为一谈。因此，在分类时，要注意事物类别对应，不能把不同类别的事物交错在一起。
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 litmus. They are more practical in this hard world. In my opinion, most people seem to belong to this group.
再如：
　　题目：Advantages of a Job Interview
提纲：
1． 现在找工作一般都要面试，通过面试，面试者和应试者可以相互了解情况。
2． 面试者可以想应试者介绍情况，如工作性质、条件、待遇等。
3． 应试者也机会给对方留下一个好的印象，如可以表现出自信心，可以介绍教   育背景、工作能力等。
Nowadays, when a person is hunting for a job, there will always be a job interview and I think the job interview has a lot of advantage. The interviewer and the interviewee can know about each other from it. First, the interviewer can tell something about the job to the interviewee such as the salary, the working conditions and something else that is relevant to the job. Then the interviewee can decide whether the job is really suitable for him. Second, I think the job interview is a good chance for the interviewee to show both his ability and confidence. Then the interviewer can figure out whether he is the right person for the job.
In a word, I think the interview will do good to both the interviewer and the interviewee. By an interview the interviewer can find a suitable person if both of them make the best of the job interview.
表示分类的名词：
种：kind, sort, type
类：group, classification, category
组成成员：member
分部/分支：division/branch
纲：class     目:order    科:family   属:genus   种:species
表示分类的动词和动词短语：
将......按.......分类:class, classify, divide, categorize, group, place, arrange...
属于某一类:belong to, fall into, be classed with,...
包括若干类:there be, contain, consist of, comprise, include, be composed of, be comprised of
组成.......类:make up, constitute, compose,....

第七节 按原因和结果展开

我们在日常对话中,经常会听到别人问为什么,自己也经常问同样的问题,所以我们对于因果推理并不陌生。在因果推理中最为重要的是合理性和逻辑性，我们会发现抽象的因果推理有时候远远不能回答别人或我们自己的问题。
实际上，任何一个因果推理都有可能是以下三个模版中的一种或多种。
模版1： 一种原因导致一种结果
模版2：一种原因导致多种结果
模版3：多种原因导致一种结果
模版1是一种理想化的因果模版，原因和结果一一对应，在解决一些简单问题的时候还是可能的，但在日常生活中的因果对应往往很复杂，所以我们经常使用的因果模版是2或模版3。当然还有很多情况下，还会发生一种超出这三种模版的情况，即所谓的因果链条。但至少在我们的写作中可以不考虑这种情况，毕竟我们只是进行习作而已。
模版的确定和推理模式的确定有密切的联系。在因果法的应用中，我们或者把原因放在前面，把结果放在后面，或者反之。模式的选择主要取决于我们要回答的问题是WHY 还是HOW。如果是前者，结果一般放前面，原因放后面；如果是后者，原因一般放在前面，结果放后面。在模版2和模版3的使用中，我们还必须注意多个原因或多个结果的排列次序，原则上我们应该把最重要的原因或结果放在最后面。下面这篇文章采用的是模版3的模式。
There are three reasons why some students cannot finish their college studies. Some students fail in college because their academic background is weak. For example, one student might not have had an adequate mathematics course in high school, so he fails his university math class. Another student may not attend classes regularly; as a result, he may not be able to pass the tests in class since he does not know the answers. Next, because of financial problems, other students may fail university classes. For example, students who have to take jobs don't have as much time to study; consequently, they may fail their classes. Others may give up their college study because they cannot stand the strain of working and studying at the same time. Finally, there are students who fail because their energies are not directed toward their classes. Some of these students are not interested in college, so they spend their days doing other things. Some other students, though enjoying college life, are distracted by other activities parties, movies, sports, etc. So they do not study enough, therefore, they fail. Because of all these problems, numerous students fail in college every year.

因果型段落只是将叙述重点集中在原因或结果之上，文章所采用的扩展模式还是列举，列举原因或结果。但在介绍原因时，可以使用举例的方式。应该说，以上虽然列举了写作中常用的几种方法，但在实际写作中，尤其是在考试当中，它们往往要结合起来用。如下面一篇文章就是学生在考试中的作文。
　　Directions:
　　A. Title: Fast Food
　　B. Word Limit: about 200 words
C. Your composition should be based on the Outline given in Chinese blow:
1. 快餐在中国十分流行，它是现代快节奏社会的最佳反映。
2. a. 快餐受欢迎有两条原因： b. 然而，从营养角度来讲，快餐却差强人意。
3. 对快餐还是以偶尔品尝为宜。
例文： Fast Food
Fast food is becoming more popular in China, especially among children and teenagers. Today, it's certainly difficult to think of any other single thing that represents the fast pace of modern society as powerfully as fast food.
There are several reasons for its popularity. First, it is very convenient and saves a lot of time. The trends of modern society seem to all point to one ultimate goal —— saving time, and fast food well serves this purpose. You just go into a fast food restaurant, order your food, and your food is ready in no time. You can either eat it there or take it away. Second, its popularity is also attributed to the clean and comfortable environment of fast food restaurants, the excellent service, and the guaranteed quality of food.
However, in terms of nutrition, fast food is far from satisfactory. It usually does not compose a balanced diet and is low in nutritional value. Thus, doctors suggest that people, especially children, eat fast food as little as possible.
Although cooking at home is time — consuming and the following washing-up tiresome, it offers healthy and delicious meals your body likes and needs. Fast food is only a good choice when you are in a hurry and turn to it once in a while. 
这篇文章既用了因果分析法，同时还用了整体对比法，阐述了快餐和在家用餐的优缺点，也用到了举例法。是多种方法的运用。