6．1段落的特征
一个好的段落应该具有以下三个特征：1）完整性（completeness）； 2）统一性（unity）； 3）连贯性（coherence）。
6．2完整性
段落的完整性指的是段落得以充分展开。作者一俟写好主题句，就应该用细节进行推展，细节越充足越好。例如，你认为“Riding motorcycles is dangerous”，你就应该用你所知道的事实证明这一观点是正确的。你可以使用数字（statistics），列举例子（example），进行描绘（descriptions）等等。
示范段落6-1
Ever since the time of the Greeks， drama has played an important role in man's lives． The Greek tragedies and come dies were a central part of the citizens' lives in ancient Greece． During the Middle Ages， Bible stories were acted out in churches，and wandering companies of players performed in the streets． In modern times， drama is brought directly into people's homes through the magic of television．
6．3示范段落分析
主题句： Ever since the time of the Greeks， drama has played animportant role in man's lives．
细节：1． ancient Greece
2． the Middle Ages
3． modern times
作者根据各个不同历史时期提供细节，举例说明戏剧的重要性。
6．4 统一性
一个好的段落应该具有统一性。统一性就是一个中心思想统领整个段落。每个细节都应支持主题句，不应有无关的细节。为了支持主题，要尽可能多地提供细节，但又要避免滥用细节。
读下面段落，然后找出毛病。
① Innovations， whether practical or aesthetic， are often resisted by the general population．② When the early experiments in the field of aviation began their work， there were many who said，“If God had wanted man to fly， he would have given him wings．③The Wright brothers made the first powered flights in a heavier-than-air craft in 1903 at Kitty Hawk， North Carolina．④Even today there are many who strongly object to modern art and music as being nothing more than “splashes of paint and honking horns．”⑤The painter Picasso's well-known masterpiece “The Three Musicians” is done primarily in blues and browns．
6．5段落分析
主题句： Innovations， whether practical or aesthetic， are often resisted by the general population．
推展细节：1． People's objection to the early experiments in the field of aviation．
2． People's objection to modern art and music．
无关细节：1． The Wright brothers' experiment in flight．
2．Picasso's painting．
显然这不是个好的段落，因为并非所有的推展句都支持主题句。应该把无关的细节删去。下图是一个有统一性的段落的结构图。
Exercise 6-1
Directions： In the folowing sentence grouping， circle the letter in front of any detail that does not support the topic sentence．
Topic Sentence：My main satisfaction in life comes from the people who are part of my life．
Supporting Details：
a． For me a day is good or bad depending on whether or not I havegooten along well with my associates．
b． I am not at all affected by the weather the way some people are．
c． For instance， my father judges his day by whether or not the skyis blue．
d． On a rainy day he is always in a bad mood．
e． What counts for me is to feel human warmth and friendship．
f． My favourite entertainment is to be with one or two intimate friends， sitting in front of a fireplace and sharing intimate recollections．
Exercise 6-2
Directions： Read the following paragraph and identify the irrelevant sentences．
① Different people spend their weekends in different ways．②Some enjoy going to the mountains to hike， ski or just relax．③Water skiing is much more difficult than snow skiing．④Others prefer going to the beach to enjoy the seashore activities and to get a suntan．⑤ Some of these people work very hard during the week；others have rather relaxing jobs．⑥ Still others like to relax by staying home and reading a good book．
Topic Sentence：________
Irrelevant Sentences：________________
Exercise 6-3
Directions： List at least five details that might used to develop thegiven topic sentence．
Topic sentence： Day dreaming has always been my favourite．
Details：1．_______________________________________________
2．_______________________________________________
3．_______________________________________________
4．_______________________________________________
5．_______________________________________________