Academic English organizes information into main (or most important) ideas and supporting details. That is, there are usually three or four major points presented, and the rest of the information serves to explain or support these main ideas:
• First main idea
• Second main idea
• Third main idea Supporting details
When reading academic English or listening to a lecture, it is important to recognize the main points. The introduction focuses your attention on the topic. Then the main points are presented, and the conclusion reminds you of one or more central ideas. Noticing the headings in a text will help you figure out the main points the writer is presenting.
1. What are two important factors that affect life in the United States?
2. What is the heading for the section that discusses the history of immigration in the United States?
3. What is cultural pluralism? 
4. What is the main idea of the section headed Making Generalizations About American Beliefs?
5. What relationship is there between the quotation at the beginning of the chapter, the introduction (first two paragraphs), and the conclusion (paragraphs 23 and 24) of the reading?
1. One factor affecting lifestyles in the United States is the different climates.
2. American Indians all speak the same language.
3. The dominant American culture was established by immigrants who came from southern Europe.
4. Throughout the history of the United States, more immigrants have come from English-speaking countries than any other countries.
3. Zangwill believed that immigrants would lose their native cultures and become something different when they came to the United States.
6. All immigrants want to assimilate to the U. S. culture completely; they have no desire to maintain their own culture.
7. U. S. immigration policy has stayed the same for the last 100 years.
8. The English language has no adjective for United States and therefore uses the term American to refer to its people.
9. It is not possible to make generalizations about what Americans believe because they are so different.
10. Many of the characteristics of Americans which Alexis de Tocqueville observed in the 1830s are still true today.