【新东方考研数学长线基础班】
既然出题侧重考查文章结构，所以一定要熟悉行文模式。下面就Pant B涉及的七选五题型的文章特点展开说明。这部分的学术文章常见行文模式有以下几种：层层递进型，即文章的几个段落是从抽象到具体、从简单到复杂的过程，各段之间为递进关系，有时这种文章的中心思想出现在层层递进的最后一段。抛砖引玉型，即文章第一段通过噱头或例子或反面观点，引出文章的讨论内容，而真正的中心出现在第一段之后。问题回答型，即文章的第一段提出一个问题，随后各段中提供该问题的答案。文章的中心思想就是该问题的直接答案。例如层层递进型文章的开头，我们可以参照下面的大纲例题进行分析。
Long before Man lived on the Earth, there were fishes, reptiles, birds, insects, and some mammals. Although some of these animals were ancestors of kinds living today, others are now extinct, that is, they have no descendants alive now. 41)__________________.
Very occasionally the rocks show impression of skin, so that, apart from color, we can build up a reasonably accurate picture of an animal that died millions of years ago. The kind of rock in which the remains are found tells us much about the nature of the original land, often of the plants that grew on it, and even of its climate.
42)__________________. Nearly all of the fossils that we know were preserved in rocks formed by w
