阅读理解。 Many people have discovered that hobbies can be profitable as well as fun. Some people have such fine collections of bottles, flags, buttons or shells that others are willing to pay to see them or they offer to buy their collections for large sums of money. Some of the best collections are owned by people who started their hobbies as young boys or girls. Some of the things that American children like to collect are stamps and dolls. Older people also save stamps, but they collect coins and things made of glass more often than dolls. Painting, writing and taking photographs are the best examples of hobbies that may become occupations . Every writer, artist and photographer probably started as a hobbyist before becoming a professional. Other hobbies that could be profitable include cooking, sewing and making things out of wood. Many doctors believe that hobbies help to make our lives more enjoyable. They believe that people who raise fish or collect recorders are too busy to spend their time worrying. Doctors also think that an active person, such as a baseball player, should have a restful hobby such as reading, while a person who sits at a desk all day should have lively hobbies such as tennis, golf or swimming. Most people in the United States agree with the doctor. It is difficult to find an American who does not have a favorite hobby. 1. The underlined word 'occupations' (paragraph3) can be replaced by ______. [     ] A. lives B. jobs C. collections D. things 2. Doctors believe that people who have hobbies ______. [     ] A. worry too much about themselves B. are very busy in their lives C. don't have time to worry D. work busily in their business 3. Almost everyone in the United States ______. [     ] A. starts his hobby during his childhood B. has a favorite hobby C. spends a lot of money on the lively hobby D. follows the doctors' advice to have a hobby 4. What can we learn from the text? [     ] A. Hobbies can cause us a lot of trouble. B. Football players should have lively hobbies C. All of the people started their hobbies from childhood. D. A writer should have tennis, golf or swimming as his hobbies.