听力原文：M: I'm so tired that I can't see straight. W: You've been tired a lot lately, haven't you? M: Well, for the last few weeks, I've had to stay up most the nights to observe star configurations for a project in my astronomy class. It's awful. No matter what time I go to bed, I always wake up at six a.m., and that's the time I usually get up. W: Your biological rhythms probably haven't adjusted to your new schedule. I've read that some people have a lot of trouble when their sleep rhythms are interrupted. Even sleeping pills don't help them. M: I know. In fact, I've heard that there me several special treatment centers for sleep disorders across the country. Some people sleep too little, scale too much, sonic sleepwalk in their sleep. W: I'd like to find out how they treat problems like that. Maybe you should go to one of these centers. M: Not me! After next week, my project will be finished and I'll go back to my regular hours. Now I know for sure that I don't want to be an astronomer. (26)