听力原文： W: Hi, Dan, [23]you know which lab you missed? You can have my notes. M: Thanks. I appreciate that. W: So how are you feeling? M: Much better now that I began taking an antibiotic. Students Health gave me one, and it's really helpful. You know what amazes me? [24] The human races survive before antibiotics. W: [24] I agree. When my father was a young boy in the 1940's, he got blood poisoning and would have died. But his doctor had heard of this new drug called penicillin. M: Wow, he was really lucky. And we have lots of antibiotics that kill bacteria. W: Well, penicillin kills bacteria, but not all antibiotics do. Some are just slowing the bacteria down until our normal immune defense can finish the job. Tetracycline(四环素) works in that way. M: Wow, how do you know all these? W: My mother used to look up all our medicines. There are lots of books around. It's interesting. What antibiotic are you taking? M: I don't remember. It's on the bottle. [25] I think I'll take a new look at the label and drop by the library to see if they have reference books on medicines. See you in the lab tomorrow. (1)