高级医学英语阅读与写作Chapter two
2012-06-02 22:49:01   来源：37度医学网   作者：  评论：0 点击：

best in the area in student achievement” rather than “Why my college is the best in the New York area”.
 
3.      It often indicates the writer's opinion or purpose rather than stating an indisputable fact. Thus, it is frequently an idea that can be disagreed with. "Because cigarettes cause diseases, pollute the air and annoy nonsmokers, they should be banned from public places" is much better than "Cigarettes are expensive."
 
4.      It should not give the writer's intention directly. "I am going to tell you about people from my country" could be changed to "Most people from my country share two common characteristics: friendly personalities and fierce national pride."
 
5.      It should contain some idea that can be supported or proved. That idea should neither too narrow nor too broad.
 
A beginning writer tends to give too broad or too narrow a topic sentence. A simple statement of fact cannot serve as a topic sentence; if a fact is used, it should be a supporting statement, as in the following:
 
I don't drink coffee.                 too narrow
I arrived there at 9:00.                    a fact, too narrow
 
On the other hand, a topic sentence should not be too broad that a complete theme or even a book would be required to support it. A paragraph should not be more than about 250 words long because anything longer tends to lose its focus on the main idea. A sentence such as "People are wonderful" cannot be supported within a paragraph because you cannot discuss, in the limited space, all the people in the world and all the ways in which they are wonderful. However, the advice might be that you narrow the statement to make a supportable topic sentence: “My neighbors were helpful when I became ill.” Consider which of the following would make a good topic sentence.
 
1.      My grandmother would do anything to help other people.
2.      My grandmother gives generously of her time to help friends and family members.
3.      My grandmother made some soup for a sick friend.
 
The first sentence is obviously too broad, surely there are some things that even a generous grandmother would not do, such as giving away her life's savings to a total stranger. This kind of overestimation is intended to impress, but it actually weakens the writing. The second one, however, would make a good topic sentence. The third one is too narrow for a topic sentence; it is a fact that needs no support but serves as a fine supporting statement. Let's make some more analysis of the following possible topic sentences on the topic “American Baseball”".
 
     Possible topic sentence                                   Analysis               
 
1.It's my purpose to discuss           clear and precise but too formal             baseball.                                              and stiff for freshman composition
 
2.The purpose of this theme          clear and precise but too               
    is to discuss baseball.                  wooden and weighty
 
3.This paper is divided into           too simple, too brief and too                
    four major sections.                    direct
 
4.Baseball is a popular                   very common
         game in America.
           
5. Baseball is the most popular    obvious inference for readers
         of American sports.
 
6.  Baseball is a game that               puzzling but stimulating
            appeals to fools.
 
7.  Baseball is a uniquely          common, attractive
     American game; those who
            would understand America
            must understand baseball.
 
The analysis clearly shows that an acceptable and reasonable topic sentence(s) must be clear and precise, attractive and stimulating, and general and inferable as in 4, 5, 6, and 7; but try to avoid being too stiff, too wooden, too weighty, too simple and too brief, as in 1, 2, and 3. Learning to write a good topic sentence is not easy, but it can be done. “To be blunt, it must be, for no essay that begins badly can be successful.”¹