第四节 把握语篇段落的展开
掌握所读材料的主旨和大意就是要求考生从短文整体上把握短文的中心思想。这个中心思想就是整篇语句表现的一个共同信息值。这一信息值的得出需要考生把每一自然段的信息联接、组织起来，形成短文的主题思想。主题思想的信息值一定等于问题加正确选项的信息值。
有的文章主题思想并不是直接由一、两个句子表述，而是通过阐述句暗示出来，这就是常说的无明确主题句，需要考生根据文中细节进行概括与归纳，即：将不同细节所集中论述的要点概括出来或者将整篇文章的所有内容综合起来，然后再下结论。在求解主题思想信息值时一定要把握短文的篇章结构，通过对篇章结构的理解，即：从因果关系、例证关系、对比关系、逻辑分析等具体内容、细节和作者的选词当中，把握主题思想。
例如
Having no language, infants cannot be told what they need to learn. Yet by the age of three they will have mastered the basic structure of their native language and will be well on their way to communicative competence. Acquiring their language is a most impressive intellectual feat. Students of how children learn language generally agree that the most remarkable aspect of this feat is the rapid acquisition of grammar. Nevertheless, the ability of children to conform to grammatical rules is only slightly more wonderful than their ability to learn words. It has been reckoned that the average high school graduate in the United States has a reading vocabulary of 80000 words, which includes idiomatic expressions and proper names of people and places. This vocabulary must have been learned over a period of 16 years. From the figures, it can be calculated that the average child learns at a rate of about 13 new words per day. Clearly a learning process of great complexity goes on at a rapid rate in children.
What is the main subject of the passage?
［A］ Language acquisition in Children
［B］ Teaching languages to children
［C］ How to Memorize words
［D］ Communicating with words
本段文章中未出现明确的主题句，但是，通篇都在谈论儿童学习语言的特点、方法及过程，研究儿童学习语言的语言学家公认，儿童到3岁时就会掌握母语的基本结构，接近交际能力。"Clearly a learning process of great complexity goes on at a rapid rate in children"。因此，我们可以得出结论说：儿童的语言学习是本篇文章的主题，答案为A项。文中没提教儿童学语言，只说过"没有语言，就不能告诉幼儿需要学什么"，所以，B项不予考虑；C项内容是如何记单词，文中并没告诉我们记单词的方法，只是提出"普通美国中学毕业生的阅读词汇是8万单词...这些词汇一定是经过16年的时间才学到等等；D项涉及用语言进行交流，而文章通篇没有"communicate"的字样，故后几项全部排除。
