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：

                                          Doctors and Teachers
 

Topic sentence
Comparison:
       Similarity 1
 
 
       Similarity 2
 
 
 
       Similarity 3
 
 
 
Contrast
Doctors and teachers are both alike and different.On the one hand,both doctors and teachers are considered professionals by their communities.The classification of professional is the highest socio-economic rank an individual can achieve in this society. In addition, both doctors and teachers can help others in their own way: doctors heal the bodies of sick people and return them to health, and teachers mold the minds of young people and turn them into responsible, educated adults. Besides, both doctors and teachers are essential members of a community. It is difficult to imagine a city or town that has no need of either a doctor or a teacher. Such a place would truly be primitive. However, on the other hand,there are
       Difference 1
 
       Difference 2
       Difference 3
 
 
 
Concluding sentence
 
 
 
many differences between the two professions. First, doctors are more highly respected than teachers by their communities. Second, as a rule, doctors can earn more money than teachers. Last, doctors have many more career options than teachers. While a doctor can maintain a private practice and, at the same time, be on the staff of several hospitals, a teacher can only be affiliated with one school at a time. All in all, it’s easy to see that although doctors and teachers both have professional status, there are many differences between them.

 
       Comparison/contrast organization
 
Topic sentence:    Doctors and teachers are both alike anddifferent.
 
                             Doctors    Teachers
                                     ↘    ↙
                                                 Alike
                                                  ↓
                                            Different
 
There are basically two ways of organizing the comparison, contrast, and comparison/contrast organizations. Take Sample B for example. The word differences in the topic sentence clearly announces that in the paragraph the two subjects will be contrasted, that is, their differences will be pointed out. The characteristics being analyzed are the following: respect by the community, salary, and career choices. Notice that the differences between the two subjects are noted in terms of each shared characteristic and the three characteristics are dealt with one by one. The way like this is termedpoint-by-point organization.
The other way of organization is to write down all the points about one of the subjects to be compared, and then to take all the points about the other subject, like the following paragraph of contrast between a liquid and a gas:
 

Topic sentence
 
 
       Subject A
       Subject B
 
 
 
The difference between a liquid and a gas is obvious under the conditions of temperature and pressure commonly found at the surface of the earth. A liquidcan be kept in an open container and fill it to the level of a free surface. A gas forms no surface but tends to diffuse throughout the space available; it must therefore be kept in a closed container or be held by a gravitational field, as in the case of a planet’s atmosphere.