【正文】 e, machines have made our life easier than it used to machines use energy, and energy is needed for heating, lighting, munications, carrying use a great deal of energy to make the things that we use and buy and 。第一句為主題句,概括地說出“我們目前的生活很大程度上依賴能源”。接著用舉例的方法從三方面說明能源的作用。下定義就是給說明對象一個明確概念。這是科學而嚴密的說明方法。它既能揭示事物的本質特征,勾勒其大概,描繪其輪廓,同時也能確定事物的范圍和界限。下定義是多方面的,可以給人、事物、思想等下定義。例如:An ideal teacher must have the following should know his subject, but he can make mistakes if he is willing to personality is as important as his ideal teacher must be should be a bit of an actor and he shouldn39。t be afraid to show his feelings and express his likes and ideal teacher is one who grows, learns, and improves himself along with his “一個模范教師”下定義的方法,關鍵詞“ideal teacher”在文中多次重復,能加深讀者的印象。分類法是對同屬不同類或同類而不同種的人或事物,根據(jù)不同性質進行分門別類地說明的方法。分類是人類認識客觀世界的重要手段之一。分類必須遵守分類規(guī)則,使分類對象具有統(tǒng)一屬性,依據(jù)同一分類標準,并使分類的子項相互排斥,不互相包蘊。例如:As far as political views are concerned, people fall into three are the conservative are opposed to sudden or great are the liberal people are in favour of progress and their opinions often seem too are the moderate moderates keep everything within reasonable are more practical in this hard my opinion, most people seem to belong to this :保守派(conservative people)、自由派(liberal people)和溫和派(moderate people),并對他們各自的特征進行了簡要的分析。事物變化的原因和結果是緊密相關的。如果某個現(xiàn)象的存在必然引起另一個現(xiàn)象的發(fā)生,那么,這兩個現(xiàn)象之間就具有因果關系。因果關系包括“由果推因”(由結果去推測原因)和“由因推果”(由原因去推測結果)兩種情況。因果關系符合人們的日常思維邏輯,因而在寫作中得到廣泛應用,常用 because, as, since, so, now that, if...then, the reason is that...等表示因果關系。例如:Of the four seasons, I like spring prefer spring because it is a season of much joy and life bursts out wear a green coaagain and colourful flowers blossom in gardens and old e outdoors for fresh air and the young plan for outdoor bees so energetic and ,末句是總結句。在主題句后, 作者用了四個句子闡述自己喜歡春天的理由。有意識地把兩種相反、相對的事物或同一事物相反、相對的兩個方面放在一起,用比較的方法加以描述或說明,指出其相同點,這種寫法叫作“比較”。指出其不同點,叫作“對照”。比較和對照各有不同的側重,但兩種方法經常結合使用。進行比較對照通常有兩種方式。第一種方式采用“先A后B”的結構,即A1,A2,A3...。B1,B2,B3...。第二種方式采用“AB交錯”結構,即A1,B1。A2,B2。A3,B3...。第一種方式采用先A后B的結構實際上是把一個段落(或一篇文章)分割為兩部分,先全面講A,再全面講B,這樣做較難收到強烈的對比效果。多數(shù)人認為第二種方式比較好,因為把對比的雙方AB逐點交錯,可以避免行文的單調沉悶,對比的效果也會更鮮明突出。例如:It is easy to be a winner can show his joy can laugh and sing and dance and celebrate his love to be with are never winners, losers are the lonely ones of the is difficult to face defeat with can not show their disappointments can not cry or grieve about their may suffer privately, but they must be posed in have nothing to celebrate and no one to share their ,闡述勝利者和失敗者的不同特征。這種寫法較易操作,但行文往往比較平淡單調。再來看看AB交錯的比較方式:I like having a twin she’s happy, I’’’m she feels unhappy, I feel the , I know what shes going to , I know what shes like what she hate what she like the same music, the same food and the same ,闡述孿生姐妹的相同特征。這種寫法較流暢自然,給讀者的印象也更鮮明突出。過程分析法就是把事物發(fā)展過程分為若干步驟,然后逐一加以分析說明。這種寫法在說明文中使用得相當廣泛。過程分析與敘事和因果關系等寫法有密切關系,但彼此又有明顯區(qū)別:敘事研究的對象是“What happens”。因果關系研究的對象是“Why it happens”,而過程分析研究的對象是“How it happens”。例如:There are several steps to plant a , dig a hole large enough for the tree, but the hole should not be too , put the tree in the hole so that it is , put the earth back into the hole it down hard with your foot several , water the tree well, as often as 。全段層次分明,連接詞語(first, second, third, finally)的使用加強了語句的連貫性。還必須說明的是,在實際寫作中,我們很少單獨采用上述幾種方法中的某一種。不少段落(或文章)的寫作都是綜合使用各種不同的寫作方法。同時還應明確,在寫作中有意識地側重使用某一種方法是有好處的。此外,上述這些說明文的寫作方法在議論文中也常被采用。如何使用這些方法,寫出一篇好的文章來,還需在平時認真積累,勤加練習。