听力原文：W: Hey, John, are you OK? Why are you frowning? M: Well, I sort of(22)have a headache. I'll be fine after a glass of boiled water and some pain-killers. That happens a lot, and I always take one or two of them whenever a headache occurs. W: A lot? Seriously? Have you ever seen a doctor? M: Of course I have. Guess what? He just told me to take some pills or let it be until the headache was gone by itself. So, I chose the first. W: Then how did you get those pills? (23) On prescription? M: (23)I had no choice. W: Now I have to tell you for your own good that it will be pretty dangerous if you go on taking those pain-relievers like this. M: How come? It's only a kind of normal medicine, and I don't take many each time. W: Well, I've read an article that said, believe it or not, (24) although most people think pain-relievers are safe, they are in fact addictive, in the same way as heroin and morphine. Some people even visit the doctor regularly on purpose to satisfy their addiction. M: You must be kidding me! Does that mean I have made myself a drug addict or something? That's terrifying ! W: Oh, don't be scared. As long as you are aware of it and pay some attention to the dose, your doctor is not likely to appear as a 'drug dealer'. M: (25) That sounds reasonable. It seems that I must take notice to these little white pills. Thank you for your information. W: My pleasure. (23)