听对话和问题,根据所听内容,选择最佳答案。 ( ) 1. A. Clean the house. B. Do the dishes. C. Do his homework. ( ) 2. A. My brother wrote it. B. My father wrote it. C. It must be a worker. ( ) 3. A. Sure. B. Of course not. C. She's not sure. ( ) 4. A. Sam. B. Tim. C. Tom. ( ) 5. A. Two hours. B. Three hours. C. Four hours.