快速識別托福段落主旨

　　很多托福閱讀段落屬于總-分結(jié)構(gòu)，即段落開始為段落主題句，其他部分為支撐細節(jié)，具體論證方式有舉例、對比比較、定義、分類、提供數(shù)據(jù)支持、類比、過程描述等，此時的段落目的對應(yīng)段落開始的主題句。例如：

　　例一(總-分結(jié)構(gòu))

　　Paragraph 7: About 90 percent of modern humans are right-handed: we are the only mammal with a preferential use of one hand. The part of the brain responsible for fine control and movement is located in the left cerebral hemisphere, and the findings above suggest that the human brain was already asymmetrical in its structure and function not long after 2 million years ago. Among Neanderthalers of 70,000–35,000 years ago, Marcellin Boule noted that the La Chapelle-aux-Saints individual had a left hemisphere slightly bigger than the right, and the same was found for brains of specimens from Neanderthal, Gibraltar, and La Quina.

　　What is the author's primary purpose in paragraph 7?

　　(A) To illustrate the importance of studying the brain

　　(B) To demonstrate that human beings are the only mammal to desire fine control of movement

　　(C) To contrast the functions of the two hemispheres of the brain

　　(D) To demonstrate that right-hand preference has existed for a long time

　　根據(jù)一般段落的總-分結(jié)構(gòu)，可以判斷首句為主題句，所以第四個選項為正確答案。文中主要描述大腦左半球的功能，未與大腦右半球的功能進行比較，所以第三個選項為干擾選項。

　　例二(總-分結(jié)構(gòu))

　　Paragraph 6: Moreover, getting petroleum out of the ground and from under the sea and to the consumer can create environmental problems anywhere along the line. Pipelines carrying oil can be broken by faults or landslides, causing serious oil spills. Spillage from huge oil-carrying cargo ships, called tankers, involved in collisions or accidental groundings (such as the one off Alaska in 1989) can create oil slicks at sea. Offshore platforms may also lose oil, creating oil slicks that drift ashore and foul the beaches, harming the environment. Sometimes, the ground at an oil field may subside as oil is removed. The Wilmington field near Long Beach, California, has subsided nine meters in 50 years; protective barriers have had to be built to prevent seawater from flooding the area. Finally, the refining and burning of petroleum and its products can cause air pollution. Advancing technology and strict laws, however, are helping control some of these adverse environmental

　　In paragraph 6, the author’s primary purpose is to

　　(A)provide examples of how oil exploration can endanger the environment

　　(B)describe accidents that have occurred when oil activities were in progress

　　(C)give an analysis of the effects of oil spills on the environment

　　(D)explain how technology and legislation help reduce oil spills

　　根據(jù)段落的總-分結(jié)構(gòu)(段落首句中的復(fù)數(shù)名詞problems說明本段落的結(jié)構(gòu)是總-分結(jié)構(gòu)——首句總論，其他句子分述幾個problems)，可以確定首句為段落主題句，即本段的寫作目的，第一個選項符合此意，為正確答案。第二個選項只是論證本身的內(nèi)容，不是段落首句所說的寫作目的。第三個選項與第四個選項都只是段落論述中的細節(jié)。

　　例三(特殊結(jié)構(gòu))

　　Paragraph 5: In addition to exploring the possible antecedents of theater, scholars have also theorized about the motives that led people to develop theater. Why did theater develop, and why was it valued after it ceased to fulfill the function of ritual? Most answers fall back on the theories about the human mind and basic human needs. One, set forth by Aristotle in the fourth century B.C., sees humans as naturally imitative—as taking pleasure in imitating persons, things, and actions and in seeing such imitations. Another, advanced in the twentieth century, suggests that humans have a gift for fantasy, through which they seek to reshape reality into more satisfying forms than those encountered in daily life. Thus, fantasy or fiction (of which drama is one form) permits people to objectify their anxieties and fears, confront them, and fulfill their hopes in fiction if not fact. The theater, then, is one tool whereby people define and understand their world or escape from unpleasant realities.

　　Which of the following best describes the organization of paragraph 5?

　　(A)The author presents two theories for a historical phenomenon.

　　(B)The author argues against theories expressed earlier in the passage.

　　(C)The author argues for replacing older theories with a new one.

　　(D)The author points out problems with two popular theories.

　　本段首句中的motives說明作者想探討戲劇起源的動機，但是作者未直接說明這些動機，而是以一個問句將戲劇起源這一現(xiàn)象戲劇化。接著給出了兩個答案，等于給一個現(xiàn)象提供了兩個解釋。第一個選項符合此意，為正確答案。

　　其實只要掌握托福閱讀文章的幾種段落組織方式，每種文章結(jié)構(gòu)的主旨詞，在托福閱讀練習(xí)中，保持對主旨詞的敏感性，熟練之后就能快速把握托福閱讀段落的主旨了，托福閱讀成績也就自然提升了。