听力原文：M: Hello, how can I help you? W: My son isn't feeling well and I'd like to get some advice. M: What seems to be the problem? W: Well, he has been coughing for several days now. I'm wondering if he should come in and see the doctor. M: How old is he? W: He is 3 years old. M: Does he have any other symptoms like fever, runny nose, or loss of appetite? W: No, actually other than the cough, he seems healthy. I am concerned though, because some of his sister's friends have whooping cough and I know that it can be very contagious. Isn't that a pretty serious illness? M: It can be serious with babies. Has your son been immunized against whooping cough? W: I'm not sure. He did get all of the suggested vaccinations. I will look it up in our records. M: If he has been immunized recently, it is very unlikely that he would catch whooping cough, even if he has been exposed. W: Sounds like I don't have to worry about that, but what shall I do about his cough? M: It will help if you give him lots of fluids and a hot bath before bedtime. Keep an eye on the cough to watch to see if it gets worse. Call us again if he has a fever or if you are still concerned. W: Thanks for your advice. M: You are welcome. Good-bye. W: Bye-bye. (23)