听力原文：M: Did you watch undersea Discover), last night? W: No, I missed it. Did you? M: Yeah, it was pretty good...It was about barnacles. W: Hmm. M: You know how they stick themselves to stuff in the ocean ... like rocks or boats? W: Uh—huh. M: Well, they do that when they're young, and then they stay in the same place forever. W: It figures. Have you ever tried removing one of those things. Last summer I tried to scrape some off a pier...I had to give up after a while. You'd think they wouldn't be able to stick like that undcrwater. M: That's one. reason scientists are-trying to figure out what their glue's made of. It's one of the strongest adhesive in nature, and it's a natural protein, so it probably wouldn't be harmful like some synthetic glues. W: Really? M: Yes. these biomedical researchers were talking about its possible uses. Orthopedists could use it for mending broken bones or it could be used in dentistry. W: I wish I'd seen that. (23)