解题思路 | 浅谈GMAT阅读文章的变体结构

GMAT阅读部分，有四大常见的结构(观点对比型、现象解释型、结论分析型、问题解决型)，然而在一些文章中，这四类结构也往往会出现一些变化，以增加文章的难度，今天我们就将以OG中出现的一篇文章为例来学习一下文章结构的变体。

例题

Conodonts, the spiky phosphatic remains (bones and teeth composed of calcium phosphate) of tiny marine animals that probably appeared about 520million years ago, were once among the most controversial of fossils. Both the nature of the organism to which the remains belonged and the function of there mains were unknown. However, since the 1981 discovery of fossils preserving not just the phosphatic elements but also other remains of the tiny soft-bodied animals (also called conodonts) that bore them,scientists' reconstructions of the animals' anatomy have had important implications for hypotheses concerning the development of the vertebrate skeleton.

分析1

文章的第一段提及了一种软体动物---conodonts，在1981年，科学家发现了它的化石残留，而这个发现对于研究脊椎动物的骨骼发展有着重要启示。

he vertebrate skeleton had traditionally been regarded as a defensive development, champions of this view postulating that it was only with the much later evolution of jaws that vertebrates became predators. The first vertebrates,which were soft-bodied, would have been easy prey for numerous invertebrate carnivores, especially if these early vertebrates were sedentary suspension feeders. Thus, traditionalists argued, these animals developed coverings of bony scales or plates, and teeth were secondary features, adapted from the protective bony scales. Indeed, externa! skeletons of this type are common among the well-known fossils of ostracoderms, jawless vertebrates that existed from approximately 500 to 400 million years ago.However, other paleontologists argued that many of the definitive characteristics of vertebrates, such as paired eyes and muscular and skeletal adaptations for active life, would not have evolved unless the first vertebrates were predatory. Teeth were more primitive than external armor according to this view, and the earliest vertebrates were predators.

分析2

第二段主要提出两个关于脊椎动物的对立的观点(traditionalists vs paleontologists)。因为文章顺序的问题，很多同学会误以为这一段的观点是基于1981年的发现得出的。然而，我们仔细观察可以发现这一段并未提及任何与1981年的发现或conodonts有关的内容。所以，实际上，第二段只是单纯地描述了两个关于脊椎动物骨骼发展的对立的观点。

The stiffening notochord along the back of the body, V-shaped muscle blocks along the sides, and posterior tail fins help to identify conodonts as among the most primitive of vertebrates. The lack of any mineralized structures apart from the elements in the mouth indicates that conodonts were moreprimitive than the armored jawless fishes such as the ostracoderms. It now appears that the hard parts that first evolved in the mouth of an animal improved its efficiency as a predator, and that aggression rather than protection was the driving force behind the origin of the vertebrate skeleton.

分析3

第三段开始再次提及conodonts，谈及发现了conodonts的一些特征，这些特征决定了它是最早的有脊椎动物，并且只长了牙(只有嘴部矿化)，最终确认了有脊椎动的骨骼发展出来是为了去捕食而非保护自身。

读完了这篇文章，我们发现实际上这是一篇观点对比型的文章，只不过作者将结构做了一些变体。一般的观点对比型文章是观点A+观点B+第三方的观点，在这篇文章中观点A是传统学者的观点，而观点B是古生物学家的观点，第三方是第一段所提及的科学家基于1981年的发现而得出的观点(即第三段)。作者只不过将第三方的观点做了一个分离，将其中一部分发现放到了第一段，作为文章的背景。如果作者将第二段放到开头，言明有两个关于脊椎动物发展的对立的观点，然后在最后才提出，1981年关于conodonts的新发现告诉我们实际上古生物学家是正确的，这便是一篇标准观点对比型的文章了。

这就是文章结构的变体，希望同学在阅读文章是多多注意这样的陷阱，这样才能更好地理解GMAT文章。