(一) 撰写引言（Introduction）的一般方法如下：

1）  统计数据或事实 Statistics / Facts：

   Each 60 seconds 3 people are killed by handguns. Handgun shootings have taken the lives of doctors, lawyers, politicians and even nuns. More people die by handgun shootings than by cancer. There must be stricter handgun law enforcement.

2）  表明主题的重要性 Importance of Topic：

    The Constitution guarantees it. The colonists were protected by it and modern day Americans insist on it. The right to bear arms means Americans should be able to purchase guns for their protection and for their sport.

3）   问题形式 Questions：

Is your husband using his computer to cheat on you? Are your kids fantasizing about sex on the internet? Do you know where your kids and spouse are? If they are in front of the computer, you might have reason to worry. There are several reasons why the computer is not “man's best friend.”

4）  曲折的接法 Zigzag：

    New York City has an international reputation for being “the city that never sleeps.” In other words, criminals work 24 hours a day in the “Big Apple.” However, if recent statistics are correct, this reputation is undeserved. In fact, New York City might be one of the safest cities in the world.

(二) 结论的写法：

1） Make a plea for a change.

    The parents, the schools and the government must make a combined effort to educate young people about the dangers of drug abuse. Moreover, the whole society must change its attitude toward such over the counter preparations as sleeping pills, diet pills and tranquilizers. The careless use of these drugs creates an atmosphere that invites the use of illegal narcotics. When we realize our full responsibility in dealing with this problem, drug addiction may begin to disappear as a national menace.

  2）Draw the necessary conclusions from what has been said.

    Thus it can be seen that the strong warnings about drug abuses heard on radio and television and seen in newspapers and magazines are not exaggeration. The evidence is overwhelming and only one overriding conclusion can be drawn: drugs are deadly, and experimenting with them can lead people and, in fact, our entire society to the point of extinction.

 3）Summarize the major points of the essay.

     Narcotics, then can affect the user in a variety of ways, most of which are frightening and dangerous. When someone tries an illicit drug, he or she may experience immediate effects such as severe hallucinations, serious mental changes and a loss of appetite. Taken over a long period of time, drugs may cause hepatitis, a complete mental breakdown, or even death from an overdose. If people can be made to truly understand these effects, the seductive appeal of drugs will disappear and thousands of useful lives will be saved from the terrifying results or narcotics addiction.

在引言及结论中的注意事项：

1）不要使用以下句子 Never use expressions like: “Now I will tell you about…” “I would like to discuss…” or “In my paper I will explain…” Such expressions are too obvious.

2）Never apologize for what you are going to write: “I do not know very much about this subject…”

3）The introduction and conclusion should not be tacked on: they should be an integral part of the whole essay.

4）The size of the introduction and conclusion should not be out of proportion to the size of the whole essay.

Topic: Should We Restrict Immigration?

正方 
PRO (Yes, we should restrict immigration.)                                        

Reasons:

1.      Immigrants take jobs from American citizens.

2.      Immigrants don't pay their taxes, and they abuse the welfare system.

3.      With their strange customs, immigrants place a strain on American culture.

反方 
CON (No, we should not restrict immigration.)

Reasons:

1.      Immigrants do menial jobs that American citizens won't do.

2.      Immigrants pay their taxes and avoid welfare.

3.      Immigrants help renew American culture by the variety of their customs.

Science: Who Needs It?

At our school all students are required to take a minimum of six courses in the natural sciences: three in the biological sciences and three in the physical sciences, regardless of the student's major. Students majoring in the humanities often have to struggle to get through these demanding courses, and their grade-point averages usually suffer as a result. It has been suggested that the requirements be modified, reducing the number of natural science courses required so that students can take more courses directly related to their majors. As a humanities major, I admit this would make college life a lot easier for me, but I still oppose the measure because natural science courses pro­vide us with a crucial part of our education.

Students majoring in the humanities usually object to taking such science courses because they claim the courses are irrelevant to their majors. “What good will physics do me when I'm teaching Spanish?” a friend of mine asked. It's true that physics, chemistry, biology, and the like may not have a direct application to most careers in the humanities, but this objection ignores one of the key issues of a university education. A university is not simply a train­ing facility; it is an institution of higher learning where students are educated, not merely trained. Even the term university implies that it's a place to obtain a general knowledge base; a university education means the student has been educated in many subjects. Since part of our universal knowledge is science, it is and logically should be a part of the university curriculum.

Humanities students might accept this argument and agree that they should take some natural science, but not as many courses as are now required. They might suggest a one-semester course in biological science and a one-semester course in physical science, along with perhaps one semester of math for non-majors. This, they argue, would expose them sufficiently to the universe of science. If the point of a university education were merely to expose students to a variety of subjects, then I might agree. But a university education implies more than mere exposure. After all, people can be exposed to subjects by watching television. Again, the purpose of going to a university is to get an education. What does that mean? It means more than just training and exposure; it means that students learn enough to become critical thinkers in the various disciplines. It means that they should gain enough understanding of the sciences, humanities, social sciences, and the arts to be able to discuss issues in these areas intelligently and to be able to question other people's views rather than just accept what people tell them.

One or two semesters of general science cannot sufficiently educate students in this field. What one learns in natural science courses is more than mere factual information. One learns to think critically, to approach problems logically, to use reasoning. And this takes time. It takes work. It takes studying different areas of science and applying the general principles in laboratory situations.

  Developing a critical ability in science is important, but why? In addition to providing the student with a universe of knowledge, an understanding of science is vital in our highly technological society. We are all confronted with issues involving nuclear waste, chemical pollutants, medical advances, exploration in space, and so forth. In order to make intelligent decisions---in fact, even to be involved in the decision-making process---people need to have an understanding of these issues that goes beyond mere ”exposure.” Otherwise, the uneducated become mere puppets who, out of ignorance, can but nod in agreement with anyone who professes expertise.

  Finally, I contend that science courses do have relevance to the humanities, and this is through the critical thinking approach of the scientific method. The scientific method is an approach to solving problems, an approach that has been tried and proven. It is an approach that demands that the researcher obtain support for his or her hypotheses. Courses in the humanities demand critical thinking as well. Students of literature must support their interpretations with “evidence” from the literary work; art majors must test their ideas---or hypotheses---by experimenting and drawing conclusions. True, in these fields one does not follow the formal scientific method, but it is the practice with that way of thinking that can benefit students in other fields.

   Science courses, then, provide us not only with knowledge that is crucial for intelligent functioning in our society, but they also provide us with the opportunity to develop our critical, logical reasoning skills. Although these courses are difficult for the nonscience majors, they are well worth the effort. The knowledge and thinking skills gained from these courses make us less vulnerable to charlatans and politicians as we more intelligently and critically evaluate the propositions offered to us.

Choose one of the following topics and write an argumentative essay.

1)      Women have achieved equality with men in society.

2)      Should schools cut back on physical education in favor of more academic courses?

3)      Should immigrants be forced to replace their culture?

4)      Mobile phone should not be banned in schools.

5)      Should doctors always be honest with their patients?