文档介绍：归纳概括主题 
( Title and Main Idea )
Paragraph 1  
      Wouldn't it be terrible if, we didn't have grass? We would have to walk on bare soil. Can you guess what our playgrounds would look like? On a rainy day we would get all muddy. On a dry day we would breathe clouds of dust.
1. The story mainly tells _________.
A. why we need rain B. how grass is kept green
C. how grass helps us D. without grass we would have to walk on bare soil
Paragraph 2
      Rats are still almost as big a danger to people as they were long ago. They still spread disease and eat crops. Much of the hunger we have today is caused by rats. They eat half of the grain harvested in the world.
2. From the passage we know _________.
A. why rats are an enemy of people B. how rats destroy our food
C. why rats cause disease D. why rats were dangerous to people long ago
Paragraph 3
      Some supermarkets have a special way of getting people e to the bakery counters. Sometimes they spray a "cake smell" into the air. At other times they spray the fresh smell of baking bread. These smells are enough to make people' s mouths water. The customers then race madly to the counter to buy cake, bread, rolls , and other baked goods!
3. The main idea of the paragraph is __________.
A. what cake smells like
B. why bakeries make money
C. how people are attracted to bakery counters
D. what bakery counters i