听下面一段材料，回答第1至4题。 1. Why did Mr. Hill's chickens lay hardly any eggs? [     ] A. Because it was winter B. Because it was very noisy C. Because it was very hot 2. What could Mr. Hill do if he wanted to earn more money? [     ] A. To lower the temperature of his chicken-house. B. To buy more and more chickens from the market. C. To put more fresh air into his chicken-house. 3. Why was Mr. Hill not interested in the owner's suggestion? [     ] A. Because it was quite cool in his own house. B. Because his wife couldn't lay any eggs for him. C. Because he only thought of how to make hens lay more eggs. 4. Which of the following expresses the main idea of the passage? [     ] A. Mr. Hill was a rich farmer who raised chickens. B. Mr. Hill only wanted to earn more money for himself. C. The owner of the company of air conditioner only wanted to sell his products.