托福閱讀文章結(jié)構(gòu)形式&閱讀技巧

我們?nèi)绻�想取得托福閱讀高分，很多情況下需要有一個宏觀的角度來看文章結(jié)構(gòu)。宏觀的結(jié)構(gòu)指的是文章是如何分布的，大致分為主旨結(jié)構(gòu)和內(nèi)容結(jié)構(gòu)。拿到一篇文章我們主要先看文章的結(jié)構(gòu)和主旨。而托福閱讀常見的五種結(jié)構(gòu)形式有：

A. 分類結(jié)構(gòu)
　　B. 時間發(fā)展結(jié)構(gòu)
　　C. 比較對比結(jié)構(gòu)
　　D. 問題解決方法結(jié)構(gòu)
　　E. 因果結(jié)構(gòu)

今天我們來看一下分類結(jié)構(gòu)的文章是如何布局和怎樣閱讀。

THE ORIGINS OF CETACEANS

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1.It should be obvious that cetaceans-whales, porpoises, and dolphins-are mammals.
　　2.They breathe through lungs, not through gills, and give birth to live young.
　　3.Their streamlined bodies, the absence of hind legs, and the presence of a fluke1 and blowhole2 cannot disguise their affinities with land dwelling mammals.
　　4.However, unlike the cases of sea otters and pinnipeds (seals, sea lions, and walruses, whose limbs are functional both on land and at sea), it is not easy to envision what the first whales looked like.
　　5.Extinct but already fully marine cetaceans are known from the fossil record.
　　6.How was the gap between a walking mammal and a swimming whale bridged?
　　7.Missing until recently were fossils clearly intermediate, or transitional, between land mammals and cetaceans.

文章第一句話講明了cetaceans這種動物有哪些，同學(xué)們在閱讀中如果遇到舉例里面不認識的單詞可以跳過，認識其中一個就可以了。第二句和第三句都在具體說明這些cetaceans有哪些特點。第四句說明這種動物很難辨別初期是長得怎么樣的，只有從化石中獲得信息。最后一句話提出一個問題：為了解決這個問題科學(xué)家就展開調(diào)查研究了。根據(jù)文章第一段，我們就知道了接下來的段落都會圍繞如何去解決這個問題而展開。托福閱讀中很多文章都是在段落第一段就提出一個問題，之后圍繞這個問題去解決。

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Very exciting discoveries have finally allowed scientists to reconstruct the most likely origins of cetaceans. In 1979, a team looking for fossils in northern Pakistan found what proved to be the oldest fossil whale. The fossil was officially named Pakicetus in honor of the country where the discovery was made. Pakicetus was found embedded in rocks formed from river deposits that were 52 million years old. The river that formed these deposits was actually not far from an ancient ocean known as the Tethys Sea.

文章第二段第一句就是承上啟下作用，我們也可以發(fā)現(xiàn)接下來的段落中都在講Pakistan這個化石的細節(jié)信息。第一句在講一個小組找到了P這個化石證明是證明和最古老的鯨魚化石有關(guān)，并且在哪里發(fā)現(xiàn)的。

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The fossil consists of a complete skull of an archaeocyte, an extinct group of ancestors of modern cetaceans. Although limited to a skull, the Pakicetus fossil provides precious details on the origins of cetaceans. The skull is cetacean-like but its jawbones lack the enlarged space that is filled with fat or oil and used for receiving underwater sound in modern whales. Pakicetus probably detected sound through the ear opening as in land mammals.

The skull also lacks a blowhole, another cetacean adaptation for diving. Other features, however, show experts that Pakicetus is a transitional form between a group of extinct flesh-eating mammals, the mesonychids, and cetaceans. It has been suggested that Pakicetus fed on fish in shallow water and was not yet adapted for life in the open ocean. It probably bred and gave birth on land.

這段在任然在介紹Pakicetus的特點以及在倒數(shù)第三句開始講和mammal之間的聯(lián)系

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Another major discovery was made in Egypt in 1989. Several skeletons of another early whale, Basilosaurus, were found in sediments left by the Tethys Sea and now exposed in the Sahara desert. This whale lived around 40 million years ago, 12 million years after Pakicetus.

Many incomplete skeletons were found but they included, for the first time in an archaeocyte, a complete hind leg that features a foot with three tiny toes. Such legs would have been far too small to have supported the 50-foot-long Basilosaurus on land. Basilosaurus was undoubtedly a fully marine whale with possibly nonfunctional, or vestigial, hind legs.

這段出現(xiàn)了一個新的化石B，具體講述了B的特點以及和mammal之間的關(guān)聯(lián)

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An even more exciting find was reported in 1994, also from Pakistan. The now extinct whale Ambulocetusnatans ("the walking whale that swam") lived in the Tethys Sea 49 million years ago. It lived around 3 million years after Pakicetus but 9 million before Basilosaurus. The fossil luckily includes a good portion of the hind legs. The legs were strong and ended in long feet very much like those of a modern pinniped. The legs were certainly functional both on land and at sea.

The whale retained a tail and lacked a fluke, the major means of locomotion in modern cetaceans. The structure of the backbone shows, however, that Ambulocetus swam like modern whales by moving the rear portion of its body up and down, even though a fluke was missing. The large hind legs were used for propulsion in water. On land, where it probably bred and gave birth, Ambulocetus may have moved around very much like a modern sea lion. It was undoubtedly a whale that linked life on land with life at sea

這段講了發(fā)現(xiàn)一個A的化石，具體介紹了A的特點和mammal之間的關(guān)系

總結(jié)：所以根據(jù)上文所有段落的介紹，我們平時在看文章的時候要注意下文章是按照什么結(jié)構(gòu)來分的。如果掌握了文章結(jié)構(gòu)，在找具體的信息和做題的時候就會心里有數(shù)，尤其是對做最后的文章主旨選擇題和表格題會有很大幫助，否則大部分同學(xué)做最后一題的時候還是按照之前的印象半蒙半猜來做的。而且對于做細節(jié)信息相關(guān)的題目也會更有把握。

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