一、時(shí)間法
在敘述一個(gè)故事或者一系列事件時(shí)，通常按事件發(fā)生的先后順序排列句子。在說明文中敘述一件事應(yīng)該遵循的程序或步驟時(shí)，也常用時(shí)間順序法?？聪旅娴睦樱?BR> After lunch， while the other girls were sunbathing， Pat and I returned to the water. Soon cramps spread from my stomach to my legs. Immobilized by pain and fear， I yelled for help. My friend thought I was joking： so she ignored me. However， Sister Theresa came to my rescue when she noticed my plight. She pulled me out of the water and administered resuscitation. When regaining consciousness， I realized how close I had come to death. My experience with near death reminds me every day how close we all are to death in our daily lives.
在這個(gè)段落里，作者用了after lunch； while……； soon； when……等時(shí)間連接語按時(shí)間的先后順序記敘了一件發(fā)生在午飯后的事。
There are four separate stages in making bread. The first stage begins by mixing yeast with warm water. This mixture is then added to half the amount of flour. The resultant batter mixture is then left for an hour. At the next stage the rest of the flour is added to the risen batter mixture， along with salt and oil. The main step in the second stage is a thorough kneading of the dough， after which it is left to rise. The third stage involves shaping the dough into loaves； the shaped loaves are then put into bread tins and left to 'prove' （rise）。 In the final stage the bread is cooked in a hot oven. The whole process of breadmaking finishes when the bread is taken from the oven and left to cool on wire racks.
這個(gè)段落采用時(shí)間順序法描述了做面包的的過程。作者用了The first stage begins by……， At the next stage……， The third stage involves…… 和In the final stage…… 等連貫性詞語詳細(xì)地按照先后順序介紹了四個(gè)步驟。
二、空間法
空間順序指按物體的空間位置（自左至右，由近到遠(yuǎn)，由上至下，由下到上，由里到外，由外到里，由中間到兩邊等順序）來展開段落。如：
The room was disgusting. By the far window was a trash can piled high with crumpled papers. In the middle of the room was a gaudy， roundsize bed littered with rotting fruit peels. The path between the bed and the doorway， where I was standing， was choked off by heaps of dirty clothes and old newspapers.
這個(gè)段落以空間順序法描寫了一個(gè)房間。先從描述遠(yuǎn)處的窗子開始，接著是房間中央，最后到作者所站的地方，由遠(yuǎn)到近地將房間里的一切描繪了出來。
Great Britain is an island that lies off the northwest coast of Europe. The nearest country is France which is 20 miles away from which Great Britain is separated by the English Channel. The island is surrounded by the Atlantic Ocean to the west， and the North Sea to the east. It comprises the mainland of England， Wales and Scotland. Scotland is in the North， while Wales is in the west. Ireland， which is also an island， lies off the west coast of Great Britain. It consists of Northern Ireland and the Irish Republic. Great Britain together with Northern Ireland constitutes the United Kingdom. Thus， the United Kingdom is composed of four parts. The largest of these is England which is divided into 43 administrative counties. The capital city is London which is situated in southeast England.
這個(gè)段落主要是采用由外到里的空間順序法進(jìn)行描寫的。先從外圍描述大不列顛的地理位置，接著從內(nèi)部仔細(xì)介紹它的各個(gè)組成部分—— 英格蘭、蘇格蘭和威爾士的相對(duì)位置，同時(shí)描述了愛爾蘭島的相對(duì)位置，最后作者又特意指出英國首府倫敦的地理位置。
三、列舉法
列舉法是通過列舉具體的細(xì)節(jié)來進(jìn)一步說明主題句所表達(dá)的主導(dǎo)思想，展開段落。列舉法如果使用得當(dāng)，能增強(qiáng)文章的說服力，使文章顯得條理清楚。用列舉法發(fā)展段落時(shí)，主題句常包含表示數(shù)量的詞，如：several， many， some， four 等。列舉細(xì)節(jié)時(shí)，可以根據(jù)各種內(nèi)容的相對(duì)重要性，按一定的邏輯順序排列。
請(qǐng)看下面的例子：
Social activities benefit us in many ways. To begin with， these activities can widen our knowledge， because we can learn what we cant from our books. Second， these activities can serve as a bridge between theory and practice， because we can learn how to put our book knowledge into practice. Lastly， these activities can enrich our experience， in that we can get to know the society well so that we can adapt to it easily when we graduate.
本段的第一句是段落主題句，in many ways在這里為下面的列舉作好了鋪墊。作者用了to begin with， second和lastly作為連接語，條理清楚地列舉了社會(huì)活動(dòng)有益的三個(gè)方面。
四、舉例法
舉例法是一種常見的展開段落的方法，它是用典型、具體而生動(dòng)的事例來證明、闡述一個(gè)觀點(diǎn)，支持主題句，使段落主題句的抽象意思具體化，使文章通俗易懂并具有說服力。但是，在寫提供實(shí)例的段落時(shí)，必須精選例子，要作到恰如其分、準(zhǔn)確地說明問題。
請(qǐng)看下面的例子：
Many old buildings in cities are still being found useful. In several cities， old buildings that were no longer being used have been converted to a variety of useful structures. For example， one school building was changed into ninetynine rental units for elderly and low income residents. In Baltimore， Maryland， six schools were converted into 132 units with the help of a fourmilliondollar city bond financing arrangement. “School House 77” in Boston utilizes three recycled elementary schools and an abandoned instrument factory. All these examples show how cities are using unneeded schools， police stations， libraries， and boardedup factories that are structurally sound and even architecturally interesting buildings.
本段的第一句是段落主題句，指出在城市里有許多舊樓還在發(fā)揮著作用。這里的“作用”是比較抽象的，不容易寫得很充分。但是作者用一些實(shí)例（如將舊校舍改建成住房提供給低收入人群等）來加以說明，主題思想就較為容易和直觀地表達(dá)出來了。
It is very difficult to evaluate another persons performance objectively. For example， Linda recently wrote irresponsible remarks about her instructor because she was failing the course. Her friend Jack wrote a marvelous description of the same instructor because he was receiving an A in the course. Both Linda and Jack were not fairly evaluating the instructor. They were influenced by the grades they were earning and were biased in their judgment.
這個(gè)段落的第一句是主題句，說明人們很難做到客觀地評(píng)價(jià)另一個(gè)人的作為。接著用Linda和Jack兩個(gè)例子來支持這一觀點(diǎn)，展開段落。例子使用貼切典型，恰如其分。
五、對(duì)比法
對(duì)比法是指通過敘述或描述兩種或兩種以上的相關(guān)事物之間的相同（相似）的地方或不同之處來表達(dá)主題。采用對(duì)比法展開段落主要通過兩種途徑：一是先敘述對(duì)比雙方的一個(gè)方面的全部細(xì)節(jié)，然后再敘述另一個(gè)方面的全部細(xì)節(jié)；另一個(gè)途徑是對(duì)逐個(gè)問題進(jìn)行雙方面的比較。
請(qǐng)看下面各例：
Why do so many graduates gravitate into business instead of into teaching？ Part of the reason is the everwidening pay gap between these two professions. A secretary， an office clerk or a bank employee can earn monthly income as high as RMB 2，000， and when one is promoted to the position of a business executive or manager， the salary is even higher. But a college graduate with a masters degree can only get a salary of RMB 1，000 per month for his teaching job. No wonder， college graduates are attracted into more lucrative（賺錢的，有利潤的） fields.
本段的主題是為什么那么多的大學(xué)畢業(yè)生從商，而不從事教學(xué)工作。作者運(yùn)用對(duì)比法，說明由于兩種職業(yè)之間存在著越來越大的收入差異，所以有好多學(xué)生畢業(yè)后選擇從商，而不選擇從教。
There are striking similarities between two of the most popular U.S. presidents， Abraham Lincoln and John F. Kennedy. Both men had their elections legally challenged. Lincoln and Kennedy are both remembered for their sense of humor， as well as for their interest in civil rights. Lincolns secretary was Mrs. Kennedy； Kennedys secretary was Mrs. Lincoln. Neither man took the advice of his secretary not to make a public appearance on the day on which he was assassinated. Lincoln and Kennedy were both killed on Friday in the presence of their wives. And finally， the same caisson（彈藥車） carried the bodies of both men in their funeral processions.
本段采用對(duì)比法通過第一種途徑展開段落。這里，作者將美國歷兩位偉大的總統(tǒng)林肯與肯尼迪從六個(gè)方面作了比較，描述他們的相似之處。
六、分類法
分類法是按一定標(biāo)準(zhǔn)對(duì)事物進(jìn)行歸類的一種段落發(fā)展方法。通過分類，可以使文章脈絡(luò)一目了然。例如：
Astronomers have been able to classify stars according to color. They have discovered that stars with different colors have different sizes， and their surface temperatures are also different. The larger a star is， the higher surface temperature it has. Stars are generally divided into five kinds： blue， white， yellow， orange and red. Blue stars are the largest ones， with a diameter of 16，000，000 kilometers. Their surface temperature is also the hottest， as high as 25，000 degrees centigrade. White stars come next， whose diameter is 2，700，000 kilometers and whose surface temperature is 11，000 degrees centigrade. Then there are yellow stars， 1，600，000 in diameter and 6，000 degrees centigrade in surface temperature. Orange stars are still smaller. They have a diameter of 1，000，000 kilometers and a surface temperature of 5，000 degrees centigrade. The smallest kind of stars appears red in color. Their diameter is only onetwentieth of that of blue stars， that is， 800，000 kilometers， and their surface temperature is only 3，000 degrees centigrade.
本段落的第二句話是段落主題句，說明不同顏色的星球其大小及表面溫度各不相同。本段落分類標(biāo)準(zhǔn)非常清楚。段落一開始就指出星球可以按顏色進(jìn)行分類。后來又明確指出星球一般被分成五種類型：蘭、白、黃、橙和紅色。接著，作者運(yùn)用分類，清楚地層層展開，發(fā)展段落。
There are two kinds of sports： “amateur” and “professional”。 Amateur athletes do not receive money for competing in sports. Olympic athletes， for example， are amateurs. They do not receive money. Professional athletes， on the other hand， do earn money. Some professional athletes earn a million dollars or more a year. They need this money to support themselves and they can save some for their future.
本段的主題句也在段落開頭，指出運(yùn)動(dòng)有兩種形式：業(yè)余的和專業(yè)的。然后，作者采用分類法發(fā)展段落，分門別類地對(duì)業(yè)余類（amateur athletes）和專業(yè)類（professional athletes）進(jìn)行解釋說明，使段落主題更明確地展示在讀者面前，段落層次清楚，中心思想統(tǒng)一明了。
Examinations fall into three kinds. One is the machinescored “objective” type. In an objective test， the students answer questions by deciding on best choice among a number of alternatives given. Another is the “completion” type. This kind of examination requires the students to add a word or phrase to complete a sentence. And the third type is the essay examination， in which the students are asked to write a composition on a given topic. All these kinds of examinations are designed to reveal what a student may have learned in any particular course.
本段采用分類法來展開段落。主題句在段落開頭，指出“考試可分三種類型”。然后，作者運(yùn)用One is the machinescored “objective type”， Another is the “completion type”，“And the third type is the essay examination” 來清楚地將考試分類闡述，段落脈絡(luò)一目了然，層次十分分明。
七、定義法
定義法是通過簡(jiǎn)單易懂而且準(zhǔn)確的語言闡明某事物的性質(zhì)和特征來發(fā)展段落，使讀者對(duì)某事物比較抽象的或是難以把握的一些特征有一個(gè)較清晰的認(rèn)識(shí)。定義法常用于說明、描寫和論證，以提供更多的具體解釋來說明某一概念或術(shù)語。
請(qǐng)看下面的例子：
Love is a very general term. It refers to a strong feeling of fondness for another person. It can happen between people of the opposite sex or between members of a family. No matter where it happens， love can always bring happiness to people.
這也是采用定義法發(fā)展段落的好例子。段落一開始，作者先指出，愛是一個(gè)常見的字眼，意義很泛。緊接著用It refers to ……來對(duì)愛（love）進(jìn)行定義解釋，清楚簡(jiǎn)單，意思明白。
Poetry is a branch of literature which explores ideas， emotions， and experiences in a distinctive form and style. Poetry， sometimes called “verse”， depends greatly on the natural rhythms and sounds of language for its special effects. Poetry， even more than prose （all other writings）， depends on precise and suggestive wording. In other words， a poem says much in little space. Poetry differs from prose in obvious ways， also. Most often the first word of every line begins with a capital letter， even in the middle of a sentence. Poems sometimes contain rhyme， and often they have a particular rhythm， like music.
本段通過下定義的方法說明什么是詩歌。段落一開始就指出詩歌是一種文學(xué)形式。作者在段落首句里用一個(gè)which引導(dǎo)的定語從句直接對(duì)Poetry進(jìn)行定義、解釋。后來，還利用同散文（prose）的簡(jiǎn)單對(duì)比，將詩歌的特點(diǎn)淋漓盡致地展示給讀者。
八、因果法
因果法是說明事態(tài)發(fā)展的原因和結(jié)果之間聯(lián)系的，常用在說明文或議論文中。可以先講原因，后給結(jié)果，也可以先給結(jié)果，后講原因。這要視實(shí)際需要而定。也有一些段落結(jié)果是顯而易見的，就集中說明原因；有的段落正好相反，就集中說明結(jié)果，因?yàn)樵虿谎宰悦鳌?BR> 請(qǐng)看下面的實(shí)例：
Homes that are improperly insulated may cause problems for their habitants. First of all， it will cost more to heat such a house than one that is well insulated. Second， it will waste energy. Third， it will make the house uncomfortable to live in because drafts or cold air is able penetrate the poorly insulated walls. Also， the poorly insulated walls could cause the inhabitants to have more colds， a health problem that results in higher expenses for doctors and medicine.
本段第一句是主題句，指出導(dǎo)致problem for their habitants 的是homes that are improperly insulated.然后集中筆墨闡明結(jié)果，在這里即problems.
So why do manufacturers keep on designing and producing VCRs that are awkward to use if the problems are so obvious？ First， the problems we notice are not obvious to technically minded designers with years of experience and trained to understand how appliances work. Secondly， designers tend to add one or two features at a time to each model， whereas you and I face all of a machines features at once. Thirdly， although finding problems in a finished product is easy， it is too late by then to do anything about the design. Finally， if manufacturers can get away with selling products that are difficult to use， it is not worth the effort of any one of them to make improvements.
段落以問句開始——為什么生產(chǎn)廠家繼續(xù)設(shè)計(jì)和生產(chǎn)那些難用的錄像機(jī)？問句之后，作者列出了四個(gè)原因。
九、綜合法
綜合法是指根據(jù)行文的需要采用兩種或兩種以上的方法來展開段落的寫作方法。
請(qǐng)看下面的例子：
Haste trips over its own heels.——忙易出錯(cuò)。Balloons have been used for sports for about 100 years. There are two kinds of sports balloons： gas and hot fire. Hot balloons are preferred by most balloonists in the United States because of their safety. They are also cheaper， and easier to manage than gas balloons. Despite the ease of operation on a balloon， pilots must watch the weather carefully. Sport balloon flights are best early in the morning or late in the afternoon， when the wine is light. Over the years balloonists have tried unsuccessfully to cross the Atlantic Ocean. It wasnt until 1978 that three American balloonists succeeded. It took them just six days to make their trip from their home in the United States to Paris， France. Their voyage captured the imagination of the whole world.
這里的第二句話是段落的主題句。本段首先運(yùn)用分類法，說明用于運(yùn)動(dòng)的氣球可以分為兩類：充氣氣球和熱氣球。接下來用了比較法，說明熱氣球要比充氣氣球安全；同時(shí)，作者還用了因果分析法說明熱氣球以其安全性能強(qiáng)為美國人青睞。整個(gè)段落綜合運(yùn)用了分類法、比較法，以及因果分析法，但是主題思想明確。各種展開段落的方法綜合在一個(gè)段落里全部是為表達(dá)主題服務(wù)的。
綜合法需要具體情況具體分析地使用，千萬不可“眉毛胡子一把抓”，或者信筆胡寫，一定要注意圍繞主題句，以說明段落中心思想為前提，保持段落意思的一致性和連貫性。
在敘述一個(gè)故事或者一系列事件時(shí)，通常按事件發(fā)生的先后順序排列句子。在說明文中敘述一件事應(yīng)該遵循的程序或步驟時(shí)，也常用時(shí)間順序法?？聪旅娴睦樱?BR> After lunch， while the other girls were sunbathing， Pat and I returned to the water. Soon cramps spread from my stomach to my legs. Immobilized by pain and fear， I yelled for help. My friend thought I was joking： so she ignored me. However， Sister Theresa came to my rescue when she noticed my plight. She pulled me out of the water and administered resuscitation. When regaining consciousness， I realized how close I had come to death. My experience with near death reminds me every day how close we all are to death in our daily lives.
在這個(gè)段落里，作者用了after lunch； while……； soon； when……等時(shí)間連接語按時(shí)間的先后順序記敘了一件發(fā)生在午飯后的事。
There are four separate stages in making bread. The first stage begins by mixing yeast with warm water. This mixture is then added to half the amount of flour. The resultant batter mixture is then left for an hour. At the next stage the rest of the flour is added to the risen batter mixture， along with salt and oil. The main step in the second stage is a thorough kneading of the dough， after which it is left to rise. The third stage involves shaping the dough into loaves； the shaped loaves are then put into bread tins and left to 'prove' （rise）。 In the final stage the bread is cooked in a hot oven. The whole process of breadmaking finishes when the bread is taken from the oven and left to cool on wire racks.
這個(gè)段落采用時(shí)間順序法描述了做面包的的過程。作者用了The first stage begins by……， At the next stage……， The third stage involves…… 和In the final stage…… 等連貫性詞語詳細(xì)地按照先后順序介紹了四個(gè)步驟。
二、空間法
空間順序指按物體的空間位置（自左至右，由近到遠(yuǎn)，由上至下，由下到上，由里到外，由外到里，由中間到兩邊等順序）來展開段落。如：
The room was disgusting. By the far window was a trash can piled high with crumpled papers. In the middle of the room was a gaudy， roundsize bed littered with rotting fruit peels. The path between the bed and the doorway， where I was standing， was choked off by heaps of dirty clothes and old newspapers.
這個(gè)段落以空間順序法描寫了一個(gè)房間。先從描述遠(yuǎn)處的窗子開始，接著是房間中央，最后到作者所站的地方，由遠(yuǎn)到近地將房間里的一切描繪了出來。
Great Britain is an island that lies off the northwest coast of Europe. The nearest country is France which is 20 miles away from which Great Britain is separated by the English Channel. The island is surrounded by the Atlantic Ocean to the west， and the North Sea to the east. It comprises the mainland of England， Wales and Scotland. Scotland is in the North， while Wales is in the west. Ireland， which is also an island， lies off the west coast of Great Britain. It consists of Northern Ireland and the Irish Republic. Great Britain together with Northern Ireland constitutes the United Kingdom. Thus， the United Kingdom is composed of four parts. The largest of these is England which is divided into 43 administrative counties. The capital city is London which is situated in southeast England.
這個(gè)段落主要是采用由外到里的空間順序法進(jìn)行描寫的。先從外圍描述大不列顛的地理位置，接著從內(nèi)部仔細(xì)介紹它的各個(gè)組成部分—— 英格蘭、蘇格蘭和威爾士的相對(duì)位置，同時(shí)描述了愛爾蘭島的相對(duì)位置，最后作者又特意指出英國首府倫敦的地理位置。
三、列舉法
列舉法是通過列舉具體的細(xì)節(jié)來進(jìn)一步說明主題句所表達(dá)的主導(dǎo)思想，展開段落。列舉法如果使用得當(dāng)，能增強(qiáng)文章的說服力，使文章顯得條理清楚。用列舉法發(fā)展段落時(shí)，主題句常包含表示數(shù)量的詞，如：several， many， some， four 等。列舉細(xì)節(jié)時(shí)，可以根據(jù)各種內(nèi)容的相對(duì)重要性，按一定的邏輯順序排列。
請(qǐng)看下面的例子：
Social activities benefit us in many ways. To begin with， these activities can widen our knowledge， because we can learn what we cant from our books. Second， these activities can serve as a bridge between theory and practice， because we can learn how to put our book knowledge into practice. Lastly， these activities can enrich our experience， in that we can get to know the society well so that we can adapt to it easily when we graduate.
本段的第一句是段落主題句，in many ways在這里為下面的列舉作好了鋪墊。作者用了to begin with， second和lastly作為連接語，條理清楚地列舉了社會(huì)活動(dòng)有益的三個(gè)方面。
四、舉例法
舉例法是一種常見的展開段落的方法，它是用典型、具體而生動(dòng)的事例來證明、闡述一個(gè)觀點(diǎn)，支持主題句，使段落主題句的抽象意思具體化，使文章通俗易懂并具有說服力。但是，在寫提供實(shí)例的段落時(shí)，必須精選例子，要作到恰如其分、準(zhǔn)確地說明問題。
請(qǐng)看下面的例子：
Many old buildings in cities are still being found useful. In several cities， old buildings that were no longer being used have been converted to a variety of useful structures. For example， one school building was changed into ninetynine rental units for elderly and low income residents. In Baltimore， Maryland， six schools were converted into 132 units with the help of a fourmilliondollar city bond financing arrangement. “School House 77” in Boston utilizes three recycled elementary schools and an abandoned instrument factory. All these examples show how cities are using unneeded schools， police stations， libraries， and boardedup factories that are structurally sound and even architecturally interesting buildings.
本段的第一句是段落主題句，指出在城市里有許多舊樓還在發(fā)揮著作用。這里的“作用”是比較抽象的，不容易寫得很充分。但是作者用一些實(shí)例（如將舊校舍改建成住房提供給低收入人群等）來加以說明，主題思想就較為容易和直觀地表達(dá)出來了。
It is very difficult to evaluate another persons performance objectively. For example， Linda recently wrote irresponsible remarks about her instructor because she was failing the course. Her friend Jack wrote a marvelous description of the same instructor because he was receiving an A in the course. Both Linda and Jack were not fairly evaluating the instructor. They were influenced by the grades they were earning and were biased in their judgment.
這個(gè)段落的第一句是主題句，說明人們很難做到客觀地評(píng)價(jià)另一個(gè)人的作為。接著用Linda和Jack兩個(gè)例子來支持這一觀點(diǎn)，展開段落。例子使用貼切典型，恰如其分。
五、對(duì)比法
對(duì)比法是指通過敘述或描述兩種或兩種以上的相關(guān)事物之間的相同（相似）的地方或不同之處來表達(dá)主題。采用對(duì)比法展開段落主要通過兩種途徑：一是先敘述對(duì)比雙方的一個(gè)方面的全部細(xì)節(jié)，然后再敘述另一個(gè)方面的全部細(xì)節(jié)；另一個(gè)途徑是對(duì)逐個(gè)問題進(jìn)行雙方面的比較。
請(qǐng)看下面各例：
Why do so many graduates gravitate into business instead of into teaching？ Part of the reason is the everwidening pay gap between these two professions. A secretary， an office clerk or a bank employee can earn monthly income as high as RMB 2，000， and when one is promoted to the position of a business executive or manager， the salary is even higher. But a college graduate with a masters degree can only get a salary of RMB 1，000 per month for his teaching job. No wonder， college graduates are attracted into more lucrative（賺錢的，有利潤的） fields.
本段的主題是為什么那么多的大學(xué)畢業(yè)生從商，而不從事教學(xué)工作。作者運(yùn)用對(duì)比法，說明由于兩種職業(yè)之間存在著越來越大的收入差異，所以有好多學(xué)生畢業(yè)后選擇從商，而不選擇從教。
There are striking similarities between two of the most popular U.S. presidents， Abraham Lincoln and John F. Kennedy. Both men had their elections legally challenged. Lincoln and Kennedy are both remembered for their sense of humor， as well as for their interest in civil rights. Lincolns secretary was Mrs. Kennedy； Kennedys secretary was Mrs. Lincoln. Neither man took the advice of his secretary not to make a public appearance on the day on which he was assassinated. Lincoln and Kennedy were both killed on Friday in the presence of their wives. And finally， the same caisson（彈藥車） carried the bodies of both men in their funeral processions.
本段采用對(duì)比法通過第一種途徑展開段落。這里，作者將美國歷兩位偉大的總統(tǒng)林肯與肯尼迪從六個(gè)方面作了比較，描述他們的相似之處。
六、分類法
分類法是按一定標(biāo)準(zhǔn)對(duì)事物進(jìn)行歸類的一種段落發(fā)展方法。通過分類，可以使文章脈絡(luò)一目了然。例如：
Astronomers have been able to classify stars according to color. They have discovered that stars with different colors have different sizes， and their surface temperatures are also different. The larger a star is， the higher surface temperature it has. Stars are generally divided into five kinds： blue， white， yellow， orange and red. Blue stars are the largest ones， with a diameter of 16，000，000 kilometers. Their surface temperature is also the hottest， as high as 25，000 degrees centigrade. White stars come next， whose diameter is 2，700，000 kilometers and whose surface temperature is 11，000 degrees centigrade. Then there are yellow stars， 1，600，000 in diameter and 6，000 degrees centigrade in surface temperature. Orange stars are still smaller. They have a diameter of 1，000，000 kilometers and a surface temperature of 5，000 degrees centigrade. The smallest kind of stars appears red in color. Their diameter is only onetwentieth of that of blue stars， that is， 800，000 kilometers， and their surface temperature is only 3，000 degrees centigrade.
本段落的第二句話是段落主題句，說明不同顏色的星球其大小及表面溫度各不相同。本段落分類標(biāo)準(zhǔn)非常清楚。段落一開始就指出星球可以按顏色進(jìn)行分類。后來又明確指出星球一般被分成五種類型：蘭、白、黃、橙和紅色。接著，作者運(yùn)用分類，清楚地層層展開，發(fā)展段落。
There are two kinds of sports： “amateur” and “professional”。 Amateur athletes do not receive money for competing in sports. Olympic athletes， for example， are amateurs. They do not receive money. Professional athletes， on the other hand， do earn money. Some professional athletes earn a million dollars or more a year. They need this money to support themselves and they can save some for their future.
本段的主題句也在段落開頭，指出運(yùn)動(dòng)有兩種形式：業(yè)余的和專業(yè)的。然后，作者采用分類法發(fā)展段落，分門別類地對(duì)業(yè)余類（amateur athletes）和專業(yè)類（professional athletes）進(jìn)行解釋說明，使段落主題更明確地展示在讀者面前，段落層次清楚，中心思想統(tǒng)一明了。
Examinations fall into three kinds. One is the machinescored “objective” type. In an objective test， the students answer questions by deciding on best choice among a number of alternatives given. Another is the “completion” type. This kind of examination requires the students to add a word or phrase to complete a sentence. And the third type is the essay examination， in which the students are asked to write a composition on a given topic. All these kinds of examinations are designed to reveal what a student may have learned in any particular course.
本段采用分類法來展開段落。主題句在段落開頭，指出“考試可分三種類型”。然后，作者運(yùn)用One is the machinescored “objective type”， Another is the “completion type”，“And the third type is the essay examination” 來清楚地將考試分類闡述，段落脈絡(luò)一目了然，層次十分分明。
七、定義法
定義法是通過簡(jiǎn)單易懂而且準(zhǔn)確的語言闡明某事物的性質(zhì)和特征來發(fā)展段落，使讀者對(duì)某事物比較抽象的或是難以把握的一些特征有一個(gè)較清晰的認(rèn)識(shí)。定義法常用于說明、描寫和論證，以提供更多的具體解釋來說明某一概念或術(shù)語。
請(qǐng)看下面的例子：
Love is a very general term. It refers to a strong feeling of fondness for another person. It can happen between people of the opposite sex or between members of a family. No matter where it happens， love can always bring happiness to people.
這也是采用定義法發(fā)展段落的好例子。段落一開始，作者先指出，愛是一個(gè)常見的字眼，意義很泛。緊接著用It refers to ……來對(duì)愛（love）進(jìn)行定義解釋，清楚簡(jiǎn)單，意思明白。
Poetry is a branch of literature which explores ideas， emotions， and experiences in a distinctive form and style. Poetry， sometimes called “verse”， depends greatly on the natural rhythms and sounds of language for its special effects. Poetry， even more than prose （all other writings）， depends on precise and suggestive wording. In other words， a poem says much in little space. Poetry differs from prose in obvious ways， also. Most often the first word of every line begins with a capital letter， even in the middle of a sentence. Poems sometimes contain rhyme， and often they have a particular rhythm， like music.
本段通過下定義的方法說明什么是詩歌。段落一開始就指出詩歌是一種文學(xué)形式。作者在段落首句里用一個(gè)which引導(dǎo)的定語從句直接對(duì)Poetry進(jìn)行定義、解釋。后來，還利用同散文（prose）的簡(jiǎn)單對(duì)比，將詩歌的特點(diǎn)淋漓盡致地展示給讀者。
八、因果法
因果法是說明事態(tài)發(fā)展的原因和結(jié)果之間聯(lián)系的，常用在說明文或議論文中。可以先講原因，后給結(jié)果，也可以先給結(jié)果，后講原因。這要視實(shí)際需要而定。也有一些段落結(jié)果是顯而易見的，就集中說明原因；有的段落正好相反，就集中說明結(jié)果，因?yàn)樵虿谎宰悦鳌?BR> 請(qǐng)看下面的實(shí)例：
Homes that are improperly insulated may cause problems for their habitants. First of all， it will cost more to heat such a house than one that is well insulated. Second， it will waste energy. Third， it will make the house uncomfortable to live in because drafts or cold air is able penetrate the poorly insulated walls. Also， the poorly insulated walls could cause the inhabitants to have more colds， a health problem that results in higher expenses for doctors and medicine.
本段第一句是主題句，指出導(dǎo)致problem for their habitants 的是homes that are improperly insulated.然后集中筆墨闡明結(jié)果，在這里即problems.
So why do manufacturers keep on designing and producing VCRs that are awkward to use if the problems are so obvious？ First， the problems we notice are not obvious to technically minded designers with years of experience and trained to understand how appliances work. Secondly， designers tend to add one or two features at a time to each model， whereas you and I face all of a machines features at once. Thirdly， although finding problems in a finished product is easy， it is too late by then to do anything about the design. Finally， if manufacturers can get away with selling products that are difficult to use， it is not worth the effort of any one of them to make improvements.
段落以問句開始——為什么生產(chǎn)廠家繼續(xù)設(shè)計(jì)和生產(chǎn)那些難用的錄像機(jī)？問句之后，作者列出了四個(gè)原因。
九、綜合法
綜合法是指根據(jù)行文的需要采用兩種或兩種以上的方法來展開段落的寫作方法。
請(qǐng)看下面的例子：
Haste trips over its own heels.——忙易出錯(cuò)。Balloons have been used for sports for about 100 years. There are two kinds of sports balloons： gas and hot fire. Hot balloons are preferred by most balloonists in the United States because of their safety. They are also cheaper， and easier to manage than gas balloons. Despite the ease of operation on a balloon， pilots must watch the weather carefully. Sport balloon flights are best early in the morning or late in the afternoon， when the wine is light. Over the years balloonists have tried unsuccessfully to cross the Atlantic Ocean. It wasnt until 1978 that three American balloonists succeeded. It took them just six days to make their trip from their home in the United States to Paris， France. Their voyage captured the imagination of the whole world.
這里的第二句話是段落的主題句。本段首先運(yùn)用分類法，說明用于運(yùn)動(dòng)的氣球可以分為兩類：充氣氣球和熱氣球。接下來用了比較法，說明熱氣球要比充氣氣球安全；同時(shí)，作者還用了因果分析法說明熱氣球以其安全性能強(qiáng)為美國人青睞。整個(gè)段落綜合運(yùn)用了分類法、比較法，以及因果分析法，但是主題思想明確。各種展開段落的方法綜合在一個(gè)段落里全部是為表達(dá)主題服務(wù)的。
綜合法需要具體情況具體分析地使用，千萬不可“眉毛胡子一把抓”，或者信筆胡寫，一定要注意圍繞主題句，以說明段落中心思想為前提，保持段落意思的一致性和連貫性。