15．聽下面一段材料，回答第18至第20題． 18．What is Sally？ A．She's a housewife． B．She's a worker． C．She's a student． 19．What does her mother always say when Sally asks her for help？ A．I will help you． B．Do it yourself． C．Ask the teacher for help． 20．Who did the cleaning that day？ A．Sally． B．Her friends． C．Her mother．
