听下面一段独白，回答第1-3题。 1. What does the research done in the Boston area indicate? [     ] A. None of tea drinkers die of heart attacks. B. Drinking tea every day can help us protect our heart. C. Patients who drink tea every day live 4 years longer than those who don't drink any tea at all. 2. How long should we exercise every day according to the speaker? [     ] A. Half an hour. B. More than one hour. C. As many hours as possible. 3. What should we do to prevent the flu? [     ] A. We should keep smiling and have a good mood. B. We should drink a bowl of water every day. C. We should make the room humid regularly.