听材料，选择答案。 1. What is Tom doing? A. He is reading a book about animals. B. He is reading a book about policemen. C. He is writing a book about animals. 2. What does Tom's brother want to be in the future? A. An animal doctor. B. A teacher. C. A policeman. 3. Why does Tom's sister want to be a singer? A. She thinks it's interesting and helpful. B. She wants to be popular and famous. C. She likes music and is good at singing.