推展段落方法之六——比较与对比法
14．1比较与对比法
有时为了说明某一事物，需要与其他事物联系起来才能阐述清楚，这就是对比或比较（comparison or contrast）。比较方法和对比方法基本一致，不同的是比较强调两事物如何相同，对比强调两事物如何不同。
示范段落14－1
Life in the city is quite different from life in the suburbs．People living in the city are constantly exposed to the hustle and bustle of urban life．But life in the suburbs is generally quiet and casual and generally more low－key than in the city．If city dwellers want to see trees and grass，they must go to one of the public parks．On the other hand，the streets of many suburban communities are lined with trees and shrubs，and each house has its own grassy yard．A person living in the city is close to many sources of entertainment，but people living in suburan areas must go into the city for entertainment．
示范段落14－2
The llama is a member of the camel family．Like the camel，the llama can live for weeks without a drink of water．Both get enough moisture from the grass，shrubs，and other plants they eat．But unlike the camel，the llama has no hump on its back．
14．2示范段落分析
示范段落14－1所用的支配方法是对比。作者对比城市生活与城郊生活。而示范段落14－2同时运用了比较和对比方法，既描绘了无峰驼和骆驼的共同点，也描绘了不同点。
14．3关于如何写比较或对比段落的建议
1）弄清比较或对比的基点
在写比较或对比时，第一步是确定比较／对比的基点。在示范段落14－1中，作者把对比基于生活步调、视野和娱乐上。在示范段落14－2中，作者把比较和对比基于无峰驼和骆驼的特性和外表上。
2）用逐事比较或逐点比较的方法组织比较或对比段落一旦确定了比较／对比基点，作者就可以用以下两种方式之一推展段落：逐事比较（item－by－item）或逐点比较（point－by－point）。
逐事比较重点放在被比较和对比的特定事物上，先叙述A事物，再叙述B事物。逐点比较重点放在两事物中每个事物的各个特征上，先叙述每个事物某一特征，再叙述每个事物的另一特征。如下面比较“a motor－cycle”和“a car”的异同的大纲所示：
Item－by－Item
Ⅰ．Motorcycle A．Expense B．Upkeep C．Safety
Ⅱ．Automobile A．Expense B．Upkeep C．Safety
Point－by－Point
Ⅰ．Expense A．Motorcycle B．Autormobile
Ⅱ．Upkeep A．Motorcycle B．Autormobile
Ⅲ．Safety A．Motorcycle B．Autormobile
3）运用连接词语保持连贯
