談托福獨立寫作主體段的論證模式

托福獨立寫作的主體段是獨立寫作最為核心的部分，主體段的論證質(zhì)量決定了整個獨立寫作的質(zhì)量和成敗。《新托福考試官方指南》對于獨立寫作論證（development）部分的說明指出：Development is the amount and kinds of support （examples， details， reasons） for your ideas that you present in your essay. To get a top score， your essay should be， according to the rater guidelines， “well developed， using clearly appropriate explanations， exemplifications， and/or details.”這段話中的引號部分是《新托福考試官方指南》中最高檔的評分標(biāo)準(zhǔn)對論證的要求，即要求“通過清晰且恰當(dāng)?shù)慕忉尅⒗C和/或細(xì)節(jié)來充分論證觀點”。那么如何才能達(dá)到論證充分的要求呢？本文筆者就提供一些實用的托福獨立寫作主體段的論證展開模式，供考生參考和學(xué)習(xí)。

“因果+例證”模式

這種模式是最為常用的一種主體段展開方式。因果論證是指通過前因后果的關(guān)系來解釋為什么段落分論點能夠支撐全文總論點。在運用因果論證時，考生可以使用一些表達(dá)因果關(guān)系的詞匯和短語來加強因果邏輯，比如表示原因的有because、as、since、now that、considering that、given that、in that、this is because、due to、owing to、thanks to、because of、on account of、as a result of、as a consequence of、“the reason why … is that”等;表示從因到果的有cause、lead to、result in、contribute to、give rise to、give birth to等;表示前果后因的有result from、attribute A to B、ascribe A to B等;表示結(jié)果的有so、thus、hence、therefore、as a result、as a consequence、consequently、accordingly、this is why等。例證是指運用更加具體的例子和細(xì)節(jié)來細(xì)化因果說理部分，且段落主題句、因果說理部分以及例子和細(xì)節(jié)之間必須相互呼應(yīng)，這樣才能夠達(dá)到主體段論證充分的要求。

下面這個段落是一位考生在考前限時訓(xùn)練時寫的。寫作的題目是：父母應(yīng)不應(yīng)該限制孩子看電視的時間？該考生選擇的觀點是父母應(yīng)該限制孩子看電視的時間，該段落闡述的理由是“看電視會影響孩子的學(xué)習(xí)”。

The first reason why I prefer to hold this position is that children may get addicted to TV as they are too young to organize their study and free time. Without limit on the amount of time spent watching TV， children may watch TV all day long， which is very harmful for their studies. As a consequence， the time they spend studying is insufficient and it is impossible for them to achieve well at school. Take my neighbor’s daughter Jessica as an example. As her father didn’t care much about how much time she spent watching TV， Jessica watched it for about six hours per day. Considering she had to go to school， there wasn’t enough time for her to finish all her homework and review what she had learned at school. After becoming addicted to TV， Jessica failed the final exams in three courses. Cases like this abound among teenagers. So I believe if parents want their children to do well at school， they have to limit the amount of time they can watch TV.

該考生首先通過因果說理解釋了為什么看電視會影響孩子的學(xué)習(xí)，然后舉出了一個具體的例子，將說理部分加以細(xì)化，表明看電視的確會影響學(xué)習(xí)。例子和說理之間互相印證，從而證明了段落的主題句。

“因果+例證+對比”模式

除了因果說理和例證之外，有時候為了充實段落內(nèi)容，更為詳盡地證明主題句，考生可以結(jié)合對比論證的手法，將對比論證和因果、舉例相結(jié)合。考生可以利用on the contrary、by contrast、however等表達(dá)引出對比的內(nèi)容。對比論證又可以分為一事物和另一事物的對比、現(xiàn)在和過去的對比、有和無的對比等幾種情況，下面分別來具體說明。

1 一事物和另一事物的對比

托福獨立寫作的某些題目會涉及一件事和另一件事的對比，或是一種做法和另一種做法的對比，或是一個物體和另一個物體的對比。為了充分凸顯自己選擇的一方的好處，考生除了證明自己選擇的一方如何好，還可以使用對比手法，證明另一方不好。

下面這個段落是一位考生在考前限時訓(xùn)練時寫的。寫作的題目是：學(xué)生一個學(xué)期學(xué)3～4門課程好呢，還是更多課程好？該考生認(rèn)為學(xué)習(xí)3～4門課程更好，不應(yīng)該學(xué)習(xí)太多課程。這個段落闡述的理由是“課程少一點，學(xué)習(xí)效率更高”。

First and foremost， not taking too many subjects contributes to effective study. Students have limited time. If they take too many subjects， there will be less time for each one. If a student studies eight hours per day and takes four subjects， he/she would have two hours to study and revise each one. However， if this student takes eight subjects， he/she can only spend one hour on each one. Obviously， two hours of study time for each subject is much better than one hour of study time， since students can understand the topic more deeply and do more practice.

該考生在論證中使用了對比論證的方法，對比了學(xué)習(xí)3～4門課程和學(xué)習(xí)更多課程的效果差別，從而有效地證明了學(xué)習(xí)更多課程不利于學(xué)習(xí)效果的提升。

2 現(xiàn)在和過去的對比

托福獨立寫作的題目中有一類題目涉及過去和現(xiàn)在的對比，或是涉及科技帶來的改變，比如：“Do you agree or disagree with the following statement？ Technology makes people’s lives simpler rather than more complicated.”對于這類題目，考生在段落內(nèi)部展開論證時就可以通過對比過去來突出現(xiàn)在。

下面這個段落是一位考生在考前限時訓(xùn)練時寫的。針對上面的題目，該考生認(rèn)為科技讓人們的生活變得更簡單了。這個段落的主題是“科技發(fā)展使日常生活變得更加簡單”。

To begin with， our daily life has been greatly simplified. Specifically， the time taken for traveling and communicating has been shortened through the advent of new modes of transportation and the media of communication. In the past， if you wanted to travel to a distant place， you might ride a horse or a bicycle and it would seem to take up the rest of your life due to the unexploited areas without roads and the extremely low speed. But nowadays， citizens are able to travel internationally within hours. In addition， many years ago， particularly in China， if you wanted to communicate with your relatives， you were supposed to rush to the post office， put your mail into the mailbox， and then the mail was transported several days later by a low-speed train. By the time your relatives received the letter and replied to you， a few months would have passed. However， today you are able to send a “to-the-point” e-mail with a click of your mouse and people will response within minutes.

在這個段落內(nèi)部，該考生從交通和通訊兩個子層面對比了過去和現(xiàn)在的差異，凸顯了段落主題句強調(diào)的“日常生活變得更加簡單”。

3 有和無的對比

在托福獨立寫作題目中，有些題目既沒有問某一事物（或做法）和另一事物（或做法）的對比，也沒有問現(xiàn)在和過去的對比，只是單純地問某一事物（或做法）的好壞，比如：“Do you agree or disagree with the following statement？ Always telling the truth is the most important consideration in any relationship.”對于這類題目，考生也可以運用對比手法來論證，此時要對比的就是“有”和“無”的差異。就這道題目而言，考生可以對比“誠實”和“不誠實”有何差異。又如，想要證明互聯(lián)網(wǎng)的好處，考生可以先說明互聯(lián)網(wǎng)帶來的方便，然后對比說如果現(xiàn)在沒有互聯(lián)網(wǎng)，人們的生活中將會有許多不方便。再比如，想要證明做某件事帶來的好處，考生可以先分析這件事的好處，再對比說明如果當(dāng)時沒有做這件事情將有什么后果。考生需要注意，因為對比的內(nèi)容并未發(fā)生，與事實相反，因此需要使用虛擬語氣。

下面這個段落節(jié)選自SAT官方給出的一篇滿分作文。這篇作文的題目是：欺騙有沒有可能是合理的？作者的觀點是欺騙總體上是不好的，這個段落是想證明“欺騙會帶來更加糟糕的后果”。這篇作文雖然來自于SAT考試，但這道寫作題目和托福獨立寫作題目的命題方式很像，托福獨立寫作的主體段也完全可以借鑒這樣的論證方式。

With regards to more serious matters， however， deception can lead to more dire consequences. Cheating in a test， for instance， may result in failing a class or expulsion from school. My brother once helped his best friend cheat in a maths test， but he confessed to the teacher immediately afterwards. The teacher only forced the two boys to retake the test because she appreciated their honesty. If my brother had not approached his teacher， he might have been kicked out of school. Furthermore， my brother’s decision serves as an example of morality to his friend and other students. Thus， he saved his friend from more serious punishment， which would have been his justification for lying anyway.

作者首先講述了哥哥幫助同學(xué)在考試中作弊，之后向老師承認(rèn)了錯誤，老師要求他們重考的事例，然后用虛擬語氣（即劃線句子）來對比論證：如果他們沒有向老師承認(rèn)錯誤，將會面臨被開除的后果。通過對比，“欺騙會帶來更嚴(yán)重的后果”這一主題得以凸顯。

“因果+例證+并列列舉”模式

并列列舉是指為了增強段落論證的充實性和論證的深度，將一個段落的理由分成并列的幾個方面來展開論述。尤其是當(dāng)段落主題句中含有抽象名詞或復(fù)數(shù)名詞時，在段落內(nèi)部可以通過并列的方式來多角度展現(xiàn)抽象名詞或復(fù)數(shù)名詞。

下面這個段落是一位考生在考前限時訓(xùn)練時寫的。寫作題目是：現(xiàn)在的年輕人是否比過去的年輕人更愛幫助別人？該考生選擇的立場是現(xiàn)在的年輕人更愛幫助別人。其中一個主體段從“現(xiàn)在的年輕人用很多傳統(tǒng)的方式幫助別人”的角度論證，下面這個段落則從“現(xiàn)在的年輕人用很多新型的方式幫助別人”的角度來論證。

Besides helping others in conventional ways， nowadays， young people tend to help others in various new ways. They take advantage of their new abilities and skills to help others. Some computer talents go to help the senior citizens in the community send emails or make contact with their children overseas; some English majors go to help foreigners as tour guides or language partners; some people with a background in economics set up new banks to help farmers invest in their farmland and expand their production.

該考生通過三個排比句來展開細(xì)節(jié)，具體論述了現(xiàn)在的年輕人如何利用自己的能力和特長來幫助別人，將段落主題句中help這一抽象名詞具體化了。

此外，考生也可以將一個段落主題句的理由細(xì)分成更具體的理由，每個理由內(nèi)部再結(jié)合一定的細(xì)節(jié)來論證。

下面這個段落是一位考生在考前限時訓(xùn)練時寫的。寫作的題目是：是否應(yīng)該在交通高峰期向司機征收一定的費用？該考生不同意這種做法，這個段落給出的理由是“這樣不僅不會緩解交通狀況，而且可能加重交通擁堵的狀況”。

Besides， charging money will not improve the traffic situation in rush hour but will bring more traffic jams. For one thing， because the fee that drivers pay for a single time may seem cheap， drivers probably don’t mind when they are asked to pay it. In this case， the fee will not prevent too many drivers from driving when the traffic is heavy. For another thing， it is difficult to take the action of charging drivers money during heavy traffic. If toll stations are set up at the entrances of the main streets， they will create a very long queue of cars outside the stations waiting to pay the fees to get through. Not only is this inconvenient， but it also makes the traffic worse and drivers may become more anxious when waiting for a long time to pass the toll stations. Thus， this action will not ease the pressure of traffic jam.

在這個段落中，該考生將理由細(xì)分成兩個方面，每個方面都結(jié)合一定的細(xì)節(jié)展開，深入闡述了為什么這樣的做法無法緩解交通擁堵狀況，甚至?xí)菇煌ǜ訐矶隆?/p>

在運用并列列舉的方法時，考生需要注意段落內(nèi)部層次和邏輯的清晰性，段落內(nèi)部不同層次之間不能交叉重疊。考生在寫作時可以使用一些表達(dá)方式來增強層次感，比如first、to begin with、to start with、besides、in addition、additionally、furthermore、finally、lastly、for one thing、for another thing等。

“因果+例證+對比+并列列舉”模式

考生也可以把因果說理、例證、對比論證和并列列舉幾種方法結(jié)合起來，使文章的論述更加豐富、有力。

下面這個段落是一位考生在考前限時寫作訓(xùn)練中寫的。寫作的題目是：20年后，學(xué)生是否不再使用紙質(zhì)書？該考生的觀點是學(xué)生將來會使用電子書，而非紙質(zhì)書。這個段落論述的理由是“電子書比紙質(zhì)書更加方便”。

Electronic books are more convenient for students to use than traditional paper books. Firstly， it is easier and time-saving for students to buy electronic books. When we want to purchase an e-book， we just need to order and pay for the book online and the book will be instantly transmitted to our iPhone or iPad. But， when we buy a paper book， even though we can also order the book online， it will be sent to our hand one or more days later. Secondly， it is easier for students to carry electronic books than heavy traditional books. Considering that students have to carry and use a lot of textbooks and reference books every day， carrying too many heavy books in their backpacks poses a great burden on students and is harmful for their physical health. On the contrary， if they use e-books， all they have to take is just an iPad or a Kindle， and it is obvious that this will greatly reduce students’ burden. Thirdly， it is more convenient for students to search for information in digital books. When we need to find some essential information in paper books， such as an important quotation， a formula， or a crucial paragraph， we need to search for the information page by page， or even book by book， which is really time-consuming. By contrast， with a digital book， we just need to type in the key words and immediately all the related information will appear on the screen. It is clear that electronic books bring huge convenience to students.

在本段的論述中，考生將電子書的方便之處拆分成三個并列的方面：購買方便、攜帶方便和搜索信息方便。考生對每一個方面都進行了說理和例證，并且都將電子書與傳統(tǒng)書進行了對比。這樣綜合運用因果說理、例證、對比和并列列舉手法充分展現(xiàn)了電子書的方便性。

總之，通過靈活運用因果說理、例證、對比和并列列舉手法，考生就可以在主體段實現(xiàn)充分論證。考生可以根據(jù)不同的題目和段落靈活選擇不同的論證組合模式進行練習(xí)，不必局限于某一種模式的單一運用，同時也要注意段落內(nèi)容的充實性和邏輯的連貫性。在保證切題的前提下，考生應(yīng)盡量在主體段充分、詳細(xì)地展開論述，以接近或達(dá)到托福官方指南中對于最高檔次作文的論證要求。