简介:2.2. Main ideaA paragraph is a group of sentences about some related subject. Reader often mistakes the topic for the main idea. But the topic is only a part of the author’s idea. The main idea of a paragraph is the combination of the topic and the controlling thought – what the author wants you to know. Readers must know what the main idea of the paragraph is in order to understand the information that they are reading.,If a paragraph contains a topic sentence,The main idea of this paragraph is despite the fact that the number of sets in the United States has virtually reached a saturation point