30 or 60 minutes on TV，they are quickly discouraged by any activity that promises less than
instant gratification．But perhaps the most serious result is the impact of television
violence on children，who have come to regard it as an everyday thing．Not only does this increase their
tolerance of violent behavior in others，but most authorities now concede that under certain conditions，some children will imitate anti－ social acts that they witness on
television．
17．3示范段落分析
主题句：Many people are worried about what
television has done to the generation of American children who have grown up
watching it．
因果模式（cause and effect pattern）：
原因（cause）：television
结果（effects）：1．TV stifles creative imagination．
2．TV causes
children to withdraw from real life experiences．
3．Children
exhibit a low tolerance for the frustrations of learning．
4．Children have
come to regard violence as an everyday thing．
17．4关于如何写因果法段落的建议
1）段落一开始就表明目的
在段落一开始就陈述你所关心的原因或结果是什么。例如，在示范段落17－1，主题句就把目的限定为分析“the effects of television on American children”。
2）选择主题要适中
选择太大的主题会给你带来麻烦。因此，记住要选择你可以驾驭的主题。例如：“effects
of television”作为主题会太大，难以下笔。然而把它限制为“effects on American children”就容易多了（第18单元继续讨论因果法）。
Exercise17－1
Directions：Write a paragraph，analyzing the effects of students cheating on exams．
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Exercise 17-2
Directions：Write a paragraph，analyzing the advantages of job interview．
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
第十八单元 推展段落方法之九——因果法（Ⅱ）
18．1原因法
有时，一个结果会源于几个原因。同样，段落可或以结果开头或以结果结束，作者可以从熟悉到不熟悉的原因逐一分析，或是从分析一个又一个读者不熟悉的原因开头，最后引出读者熟悉的结果。选用哪一种，决定于作者认为哪一种更有说服力。
示范段落18-1
Several changes have brought wild animals to the cities．Foremost is，that air and water quality in many
cities have improved as a result of the 1970's pollution control efforts．Meanwhile，rural areas have been built up，leaving many animals on the edges
of suburbs．In addition，urban wildlife refuges have been
created．The Greater
London Council last year spent ＄750,000 to buy land and build 10 permanent wildlife refuges in the
city．As a result，many big birds are now living in
the city．For peregrine
falcons cities are actully safer than rural cliff dwellings．By 1970 the birds had died out east
of the Mississippi because DDT had made their eggs too thin to support life．That year，scientist Tom Cade of Cornell
University began raising the birds for release in cities，for cities afforded plentyof food．
18．2 示范段落分析
主题句：Several changes have brought
wild animals to the cities．
因果模式（Cause-effect Pattern）：
结果（Effect）：wild animals back to the cities
原因（Causes）： 1．Air and water quality have improved．
2．Rural areas
have been built up．
3．Urban
wildlife refuges have been created．
18．3 因—果—因法
有时候，一个原因也许会引起一个结果，这个结果又成为另一个结果的原因，如示范段落18-2所示。
示范段落18-2
For some time now，medical scientists have noted an alarming increase in disease of the
heart and circulation among people who smoke cigarettes．It has been found that the presence
of nicotine in the blood stream causes blood vessels to contract，thus slowing circulation，which eventully leads to hardening
of the arteries．As the
arteries stiffen，less blood
reaches the brain，and the end
result of this slowdown is the cerebral hemorrhage，commonly referred to as a“stroke”．In addition，nicotine in the bloodstream reduces
the ability of the hemoglobin to release oxygen，resulting in shortness of breath．The lack of oxygen forces the heart to beat faster—that is，the pulse rate increases—and in turn accelerates the risk of
heart attack．
18．4．示范段落分析
因-果-因模式（Cause-Effect-Cause
Pattern）：
Smoking tobacco→nicotine in the blood streams
→the blood vessels constract…
18．5 关于写因果段落的建议（续）
3）着重分析直接的、明显的原因
每个结果都有无数的原因，同样，每个行为都会导致无数的结果。因果段落应只着重分析直接的、明显的原因，忽略间接的原因。例如，一个学生成绩不好，直接原因是没有认真学习，间接原因也许是对学校不满。显然，我们应该着眼于直接的原因而摒弃间接的原因。
4）根据重要性或熟悉程度排列细节（见第19单元）
5）使用适当的排列符号（listing
signals）（见第34单元）
Exercise 18-1
Directions：Read the following paragraph of cause and effect，adding suitable listing signals and
linking expressions．
There are many reasons why languages change．____，
various languages that started from the same parent developed their
own uniqueness after groups of speakers drifted away from one another to
establish isolated，independent communities．________is the independence of and interaction with foreign cultures，often as a result of military
conquest．________is
rapidly expanding technologe and new systems of communication that bring all
cultures and languages into close contact，with borrowing between languages a common phenomenon in the
contemporary world．All languages change as the experiences of their speakers change．
Exercise 18-2
Directions：Write a paragraph analyzing the causes of students cheating on exams．
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
第十九单元 组织段落方法——重要性和熟悉度顺序
19．1 重要性顺序排列法
前面我们已经讨论了组织段落的两种方法——时间顺序法（time-order）和空间顺序法（space-order）。组织段落的第三种方法是根据重要性排列的方法（to organize
details according to their order of importance）。作者使用这种方法的依据是他认为所选用的细节应如何加以强调。
使用重要性顺序法，可选用上升顺序（ascending order），或下降顺序（aescending oraer）。前者先列举次要观点，把重要的留到最末（如示范段落17-1），后者先强调最重要的观点，然后列举次要观点（如示范段落4-1）。
19．2 熟悉度顺序排列法
对于某些段落，也许使用熟悉度顺序法（order of
familiarity）更恰当。这种方法根据读者对作者所选用的一系列细节的熟悉程度排列。例如，在分类段落中，作者经常先谈论读者比较熟悉的、具体的细节，然后谈论读者不大熟悉的细节，如示范段落16-1。
19．3 使用顺序法的一般准则
到目前为止，我们共讨论了四种组织段落顺序，使用哪一种顺序取决于作者的写作目的和读者对主题的熟悉程度。
1）如果你要说服别人相信一个观点，应该选用重要性顺序，把最好和最有力的理由放在能使读者最容易牢记的地方——段末。
2）如果你要向读者准确地展示一个场面，则应选用空间顺序描述，以便你的读者能够在脑海中再现你所描绘的画面。
3）如果读者对你要谈论的话题不大熟悉，则应从熟悉的观点着手。
4）如果你要告诉读者发生了什么事情或怎样做某件事，则需要时间顺序。
Exercise 19-1
Directions：Read the following two paragraphs and analyze their orders of
organization．
（1）
Why are young people so enthusiastic about computers？It is mainly because they find that
the computer has a large number of desirable properties．First，it's not terribly demanding，and it does what it is told．Second，it's easier
to be a friend to a computer，for it won't make fun of you．Nor does it scold you or talk back．Third，the computer
is more interesting than any other object．Like people，it is interactive．When you ask it a question，it gives you an answer．And because it stores great quantities of information，it can oftenanswer more questions，more accurately，than human friends．Finally，by programing a computer，a youngster can create a world of
his own．
Topic Sentence：____________________________________________
______________________________________________________________
Developing Method：_________________________________________
Details：1．_______________________________________________
2．_______________________________________________
3．_______________________________________________
4．_______________________________________________
Order of Organization：________________________________________
（2）
People travel because travel benefits them in a number of ways．First，it enables people to derive much pleasure from seeing sight sand
snapping pictures．Second，it provides an effective way to get
their mind off their work．It relieves them from strain and makes them thoroughly relaxed and
ready to resume their work with rennewed efforts．Third，it offers an
opportunity to visit old friends and make new friends，too．Finally，it allows people to see new customs，learn new things，gain new experience and enables them to come back with broader mind．
Topic Sentence：____________________________________________
______________________________________________________________
Developing Method：________________________________________
Details：1．______________________________________________
2．______________________________________________
3．______________________________________________
4．______________________________________________
Order of Organization：______________________________________
Exercise 19-1
Directions：Write a paragraph about the unfavorable effects of advertisements，using order of importance．
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Exercise 19-2
Directions：Write a paragraph about the phenomena of the wasting of water，using order of familiarity．
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
第二十单元 推展段落方法——混合方法
20．1 混合方法（Mixed Patterns）
到目前为止，我们讨论了九种推展段落方法——1）事实数据法（facts and statistics）；2）叙述法（narration）；3）描述法（description）；4）过程分析法（process analysis）；5）定义法（definition）；6）举例法（examples）；7）比较对比法（comparison
and contrast）；8）分类法（division and classification）；9）因果法（cause and effect）。我们还讨论了四种组织段落的方法：1）时间顺序法（time
order）；2）空间顺序法（space order）；3）重要性顺序法（order of importance）；4）熟悉度顺序法（order
of familiarity）。此外，我们还谈及一个好的段落的三个特征：1）完整性（completeness）；2）统一性（unity）；3）连贯性（coherence）。
我们在前面各单元的示范段落中已经发现，极少段落是仅用一种推展方法的。作者常常在段落中使用一种方法作为支配方法（dominant method），另外一种或数种作为辅助方法（supporting method）。
示范段落20-1
Man's knowledge of the past has sometimes been gained in odd ways．One of the oddest incidents
occurred on January 16，1900．An angry
workman broke a crocodile mummy into pieces．He wassurprised to find that the mummy had been wrapped in sheets of
papyrus，the reed
paper of ancient Egypt．And on the papyrus there was writing．
20．2示范段落分析
主题句：Man's knowledge of the past has
sometimes been gained in odd ways．
组织段落顺序：Time order
支配推展方法：Example
辅助推展方法：Narration
示范段落20-2
There are two kinds of memory：short-term and long-term．Information stored in the long-term memory can be recalled at a
later time when it is needed．The information may be kept for days or weeks．In contrast，information stored in the short-term
memory is kept for only a few minutes，usually by repeating the in formation over and over．
20．3示范段落分析
主题句：There are two kinds of memory：short-term and long-term．
组织段落方法：Order of Familiarity
支配推展方法：Division and Classification
辅助推展方法：Description，Contrast
Exercise 20-1
Directions：Write a paragraph on population increase，using cause and effect as the
dominant method，and examples，facts or statistics as the
supporting methods．
Why has the world population been increasing so rapidly in the last
decades？_____________________________________________________
__________________________________________________________________________________________________________________________________________________________________________________________
Exercise 20-2
Directions：Write a paragraph on why you chose your specialty，combining the various methods you
have learned．
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Exercise 20-3
Directions：Write a paragraph about whether weekend homework should be abolished．
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Exercise 20-4
Directions：Write a paragraph about your favourite season．
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
第二十一单元 从段落到篇章
21．1 段落和篇章
段落和篇章在长度上有明显的不同，但是它们在结构上是一致的。首先，段落是由表达其主题思想的主题句（Topic Sentence）或主题导句（Topic Introducer）引出的，而篇章中的首段也是该篇文章主题思想的导言和引言；其次，一个段落必须有若干个展开句使主题思想得以展开和充实，同样篇章的主体部分也是由几个推展或后续首段主题思想的段落组成。再者，在段落结束时有一个结尾句（Concluding Sentence）总结段落的主旨，篇章也同样有一个对上下文进行归纳和总结主题思想的末段。尽管不是所有的段落和篇章都具备这样的完整结构，但典型的段落和篇章在结构上是一致的。
根据上述，让我们比较一下Model Paragraph 21-1和Model Essay 21-2，后者的主题思想完全基于前者。所不同的是，Model Paragraph中的六个句子①，②，③，④，⑤，⑥均已被扩展成Model Essay中的六个段落。
Model Paragraph 21-1
①To be successful in a job interview，the applicant should demonstrate
certain personal and professional qualities．②In as much as the first and often lasting impression of a person isdetermined
by the clothes one wears，the job applicant should take care to appear well-groomed and
modestly dressed，avoiding the
extremes of too elaborate or too casual attire．③Besides care for personal appearance，one should pay close attention to one's manner of speaking，which should be neither showy nor
too familiar but rather straightforward，grammatically accurate，and friendly．④In addition，one should be prepared to talk knowledgeably about the requirements
of the position for which one is applying in relation to one's own professional
experience and interests．⑤And finally，there ally impressive applicant must convey a sense of
self-confidence and enthusiasm for work，factors which all interviewers value highly．⑥The job seeker who displays these
characteristics，with just a
little luck，will
certainly succeed in a typical personal interview．
Model Essay 21-2
①To be successful in a job interview，you should demonstrate certain
personal and professional qualities．You need to create a good image in the limited time available，usually from 30 to 45 minutes．Furthermore，you must make a positive impression
which the interviewer will remember while he interviews other applicants．A tall times，you should present your most
attractive qualities during an interview．
②You should，for example，take care to appear well-groomed
and modestly dressed，avoiding the extremes of too elaborate or too casual attire．On the positive side，clothes may be a good leveller，putting you on a par with other
