如何用定义与分类法推展篇章
25．1 Definition and Classification（定义与分类）
A writer often employs more than one method of development in an essay．In order to make it easier or clearer for the reader，the author may，for instance，decide to classify objects，events or terms by retaining a few classes rather than many specific items．Additionally，he may need to define the lables he uses in classifying the subject，especially if the lables are not widely known or are abstract．
在进行定义或分类写作时需注意：1）在进行诠释（定义）时，一定要具体、确切；2）分类时要周密，标准必须对应划一，不能交错重叠。
Model Essay 25-1
Nowadays，more and more people have books in their homes，but few of them really ‘own’the books．In Professor Adler's opinion，there are three kinds of book owners．The first kind of owners have all the standard sets and best-sellers-books that are sold in very large numbers—unread，untouched．（These owner sown only wood pulp and ink，not books．）
Another kind of book owners have a GREat many books—a few of them read through，most of them dipped into，that is，most ofthe books are only read or studied for a short time or without much attention；but all of them as clean and shiny as the day they were bought．（These persons would probably like to make books their own，but are restrained by a false respect for their physical appearance．）
The final kind of book owners，however，have a few books or many，every one of them do geared（having the corners of the pages bent down with use，like a dog's ears） and dilapidated（broken and old，falling to pieces），shaken and loosened by continual use，marked and scribbled in from front to back．（These men really own books．）
Do you aGREe with Pr of．Adler？
25．2 Analysis of the Model Essay（范文分析）
In the above model essay，according to the writer，book owners can be divided into three kinds．They are as follows：
1）Owners with all standard sets and best-sellers—unread，untouched；
2）Owners with a GREat many books，a few of them read through，most off them dipped into；
3）Owners with a few books or many，every one of them do geared，dilapidated，shaken and loosened…
根据范例所示，我们得知作者将有书的人划为三类，其分类根据是划一的，分出的三类book owners互相排除，没有重叠。作者还通过使用“the first kind…another kind…the final kind…”等这些转换词语，有机地围绕主题“There are three kinds of book owners”，介绍了三种不同类型的“owners”。此外，作者还将一些读者不知或概念不清的词、词组，如“bestsellers”，“dipped into”，“do geared”，“dilapidated”等下了定义，这便达到了使读者完全领会其意的目的。
