推断短文的主旨大意题是阅读测试中测定考生阅读能力经常出现的一种题，也是考生感到最为棘手、最容易出错的题。在PETS三考试中，主旨推断题不仅频繁出现在阅读测试中，还专门设有一个大题（61-65）全部是有关主旨的。主旨推断题要求考生具有很强的话语篇章把握能力和分析能力，能够从全局的角度对文章括以总领，梳清脉络。可以说，对阅读理解主旨题的把握能力决定了阅读这个整体题项的成败，它也是衡量阅读水平高低的一个重要标尺。所以，如果我们在这个题上能够取得突破，就等于是攻克了阅读当中最顽固的堡垒，其它类型的题也就不在话下了。所谓主旨大意题指针对段落或短文的subject(主题)、main idea(主题思想)、title(题目)或purpose(目的)拟题。尽管题型或用词不尽相同，但所针对的都是段落（或短文）的主旨大意。以下是针对段落（或短文）的主旨大意所设立的常见题型：
　　1. What is the main idea of this paragraph(passage)?
　　2. What is the author′s main point?
　　3. The main idea (central thought)of the paragraph(passage)is--------
　　4. Which of the following sentences best expresses the main idea?
　　5. What does the paragraph (passage)mainly suggest?
　　6. The main point of the paragraph(passage)is-----
　　7. The paragraph (passage)centers on the point that---------
　　8. The author seems to be especially interested in------
　　9. The topic sentence of the paragraph(passage)?
　　10. What topic is treated in this paragraph(passage)?
　　11. What the paragaph (passage) tells us would be summarized by the sentence---
　　12. The best summary of the paragraph (passage)is that ---
　　13. The paragraph (passage)informs us that---
　　14. We can infer from the paragraph (passage)that----
　　15. What does this paragraph (passage) imply?
　　16. What is the subject of this paragraph (passage)?
　　17. Which of the following can be concluded from the information presented in this paragraph (passage)?
　　18. What conclusion can be drawn¹ from this paragraph (passage) ?
　　19. The (main) subject  of the paragraph (passage) is----
　　20. Which of the following best states the theme of paragraph (passage)?
　　21. The paragraph (passage) states (illustrates, discusses, deals with, is concerned about, describes)-----
　　22. The main purpose of this paragraph (passage) is that ---
　　23. What is discussed (talk about)in this paragraph (passage)?
　　24.The main (primary)purpose of the paragraph (passage)?
　　25. What is the author’s main purpose?
　　26. The primary objective of the paragraph (passage) is---
　　27. The paragraph (passage) indicates that---
　　28. Which of the following is true?
　　29. Which of the following would be the best title for this paragraph      (passage)?
　　30. The title of this paragraph (passage) would be----
　　31. The title that best expresses the main idea is---

　　在各类英语考试阅读理解题中，推断主题大意题所占比例较大，几乎每一文章都设一个主旨题。出题者意在通过此题考查考生语篇能力。那么，怎样才能准确地把握住短文的主旨大意呢？从以下的实例说明我们便可得到满意的回答。

　　All students of geography should be able to interpret a weather map accurately². Weather condition an enormous amount of information about wealth condition existing at a time of observation over a large geographical³ area. They reveal in a few minutes what otherwise would take hours to describe. The United States Weather Bureau issues information about approaching storms, floods, frosts, droughts, and all climatic conditions in general. Twice a month it issues a 30-day “out-look” which is a rough guide to weather conditions likely to occur over broad areas of the United States. These 30-day out-looks are based upon an analysis of the upper air levels which often set the stage for the development of air masses, frosts and storms.

　　大至每篇文章，小至每一段落，都必然有一个主题。这是因为任何文章（或段落）都是为了向读者说明一个段落或阐述一个观点。因此，我们在实际处理这一类型的题时，最关键、最根本之处就在于怎样去分析、把握文章（或段落）的主题。

　　一篇文章（或一个段落）可以有很多的次要思想（minor⁴ ideas）h和论证性细节（supporting details）,但中心论点或主题思想（theme,main idea）一般只有一个。中心思想起主导作用，论据是主题的从属，它们之间是“主干”与“分枝”的关系。在考试中，如果这种关系没弄清楚，必然导致判断错误。现以上文为例，综观全文，我们发现，原文从第二句开始以下各句都是围绕着第一句这个中心来解释：Why should they develop this ability?作者是从几个方面加以解释：一是map信息包容量大；二是覆盖面大；三是速度快；再就是可作为期三十天的气象展望；还可有效地预报灾难性天气。而作为一个学地理的学生看懂这样的气象图是必不可少的。所以说原文第一句和下文是一种主从关系。了解了这一点，就不难推断出本段的主题思想了。