(6)原因和結(jié)果 因果分析是常用的拓展段落的方法之一，一定要注意推理的邏輯性因果關(guān)系必須表達(dá)清楚，不能因果混淆，更不能因果倒置，要避免牽強(qiáng)附會(huì)和循環(huán)論證。一個(gè)原因可能造成一個(gè)或多個(gè)結(jié)果，也可能在一大段文章中涉及到一連串因果關(guān)系。一個(gè)結(jié)果也可能由多種原因所引起，通常先寫(xiě)結(jié)果，后寫(xiě)多種原因；但也可先寫(xiě)原因后寫(xiě)結(jié)果。另外，如果喲啊強(qiáng)調(diào)原因或結(jié)果，可用倒裝或強(qiáng)調(diào)句型加以突出。例如：
The surge of demand for oil will soon begin to send shock waves through the American economy and transportation system. The impact of these tremors can already be anticipated: to the consumer they signal the end of a long love affair with the car, and to Detroit they offer an early warning that its 1985 growth aims are dangerously unrealistic. Unless we exercise foresight and devise growth-limits policies for the auto industry, events will thrust us into a crisis that will lead to a substantial erosion of domestic oil supply as well as the independence it provides us with, and a level of petroleum imports that could cost as much as $20 to $30 billion per year. Moreover, we would still be depleting our remaining oil reserves at an unacceptable rate, and scrambling for petroleum substitutes, with enormous potential damage to the environment.
(7)定義法 有時(shí)候?yàn)榱吮苊饣煜蛘`解，我們必須對(duì)一個(gè)詞、一條術(shù)語(yǔ)或諺語(yǔ)、一個(gè)概念通過(guò)下定義加以說(shuō)明、解釋。通常有三種方法下定定義：給出同義詞、用一個(gè)帶有定語(yǔ)從句的復(fù)合句或用一整段文章，而以第三種方法最為常用。1997年1月份四級(jí)考試的作文Practice Makes Perfect就是一篇極為典型的定義型文章。再看下面的例子：
A "liberated woman" is simply a woman who controls her own life, rather than allowing it to be controlled by other people, traditions, or expectations. A "liberated woman" can be found pursuing any line of work, including housework, or no work at all. She may or may not be married; she may or may not have born children. She may belong to any race; she may have attained any age. She need have only one trait in common with her "liberated sisters": she makes her own choices, whether they be the colors on her walls or the advanced degrees she seeks. She acts of her own volition, responsible to herself, and not out of fear of what her mother, lover, or neighbor might say.
(8)分類(lèi)法 所謂"分類(lèi)"就是根據(jù)人物和事物的特征將他們/它們分別歸入各自不同的范疇。在寫(xiě)這一類(lèi)段落時(shí)，一定要抓住各個(gè)類(lèi)別的典型特征，不要異類(lèi)相串，混淆起來(lái)。例如：
According to Xiao Li, the fifteen students of his class fall into three groups. Seven of them work hard and study well. They always get good marks in examinations and are often praised by the teachers. Li calls them "good students". The monitor, the secretary of the Youth League branch, and the captain of the class volleyball team, are quick in finding out what their fellow students are interested in or what they should do as a collective. They always organize proper activities at the proper time, so Li calls them "good organizers". Four other students are very kind to their classmates, always ready to lend them a helping hand. They help to clean the classroom and the corridor even when they are not on duty. Li says that they are "good fellows". "What about yourself?" someone asks him. "I’m a group by myself-a good observer."
