听材料，回答问题。 1. Who is Harry Potter? A. He's a cartoon character. B. He's JK Rowling's son. C. He's created by JK Rowling. 2. What did three children get while reading the Harry Potter books for long hours? A. A headache. B. A cold. C. A toothache. 3. How long did each patient spend reading the Harry Potter books a day? A. Less than four hours. B. More than four hours. C. Four hours. 4. When did the headache go away? A. Before they began to read the books. B. While they were reading the books. C. After they finished reading the books.