例1
In rock music there is a distinct and almost overwhelming beat．No single beat is characteristic of the music today. But each song has an easily recognizable rhythm．As you listen to a son9，your foot usually starts to pick up the beat．Before lon9，your entire body seems to be moving with it．Your head pounds with the beat，and there is no room for thought．Only the surge of the music is important．In its own way，rock music is as dominant as the rock Gibraltar. Its message is an evergrowing emotional one．
在这一段文章中 “In rock music there is a distinct and almost overwhelming beat.” 为主题句。beat则是句子的信息核心。该词在第2、4、6句里重复出现，而第3句中的“rhythm”(节奏)跟“beat”(强烈的节奏)意思基本一致，这就保证了主题平稳而持续的发展。请注意：第8、9句作者重申并总结了主题句，而不是说段末是主题句。

例2
    The vegetable and fruit and flower merchants are surrounded by baskets of purple eggplants， green peppers，strings of tiny silvery onions，heads of bitter Indian spinach．and a dozen Indian vegetables for which I don’t even know the English names．I had forgotten about the profusion of fruit in India—it is only during the brief intense summer that you see much variety of fruit in Moscow. In Russia，as winter approaches all vegetables except for potatoes and the pervasive cabbage in soup seem to disappear from the menus．
主题句在中间的第二句“I had forgotten about the profusion of fruit in India—it is only during the brief intense summer that you see much variety of fruit in Moscow.”

例3
    People live in cities today think that meat is something that comes wrapped in cellophane．from the supermarket，potatoes come by the pound in plastic or paper bags，and feather grows in hats. The city dwellers’ views are quite different from the views of their ancestors, who knew that? meat is hunted down in the forest，potatoes are planted and weeded，and only birds can produce1eathers. Yet, whether people today realize it or not，they are still as dependent on animals and plants for their existence as their ancestors were．
主题句为最后一句 “Yet，whether people today realize it or not，they are still as dependent on animals and plants for their existence as their ancestors were.”
以上为叙述的方便并考虑到篇幅的限制，只选单段短文为例。实际上阅读理解题中大部分是多段短文。但主题句一般出现在起始段。
B．概括和归纳出主题思想。实际上，在阅读理解测试部分有的文章是没有主题句的。这是由于文章的体裁不同或是由于阅读的短文是从篇幅较长的文章中节选的。这时就要靠读者自己进行概括或归纳隐含的主题思想了。概括主题可以从归纳每段的要点开始(大部分阅读理解短文都是由数段组成)，最后将各段要点集中概括并归纳出全文的主题思想。下面不妨考察几个例子：
 
例4
A bus driver must answer questions while guiding a bus through heavy traffic. All day long, the driver answers the same questions without becoming angry. Every few minutes a bus driver has to ask passengers to step to the rear of the bus. In spite of traffic snarls and thoughtless passengers who cause delays, a bus driver is expected to cover his or her route on schedule.
这一段的隐含主题句可概括为“Driving a bus is hard work.”

例5
A green I-538 form is used by international students in order to obtain permission from the Immigration and Naturalization Service to transfer from one university to another in the United States. If you are planning to transfer, remember that you must obtain the permission before leaving the university where you are currently studying. You must complete the form I-538, have it signed by the foreign student advisor, and submit it to the District Office of the Immigration and Naturalization Service together with the form I-20 from the new school and the small, white form I-94 that was affixed to your passport when you entered the country.
Submitting the signed 1-538 and other documents does not insure permission to transfer. Only an official of Immigration can decide each case. Students who have not completed one term of study at the school that issued them their first I-20 are not advised to file for permission to transfer until they have completed one term.

这篇短文的隐含主题旬可归纳为 “What should an international student d0．if he or she wants to transfer from one university to another in the United States."