听力原文：W: Sir, you' ye been using the online catalogue for quite a while , Is there anything I can do to help yon？
M: Well, I've got to write a paper about Hollywood in the 30s and 40s, and I' m really struggling. There are hundreds of books, and I just don' t know where to begin.
W: Your topic sounds pretty big. Why don't you narrow it down to something like...uh'" the history of the studios during that time？
M: You know, I was thinking about doing that, but more that 30 books come up when I typed in "movie studios.
W: You could cut that down even further by listing the specific years you want. Try adding "1930s" or "1940s' or maybe "Golden Age.
M: "Golden Age" is a good idea. Let me type that in ... Hey, look, just 6 books this time. That' s a lot better.
W: Oh... another thin you might consider.., have you tried looking for any magazine or newspaper articles？
M: No, I've only been searching for books.
W: Well, you can look up magazine articles in the Header' s Guide to Periodical Literature. And we do have the Los Angeles. Times available over there. You might go through their indexes to see if there' s anything you want.
M: Okay, I think I'll get started with these books and then I'll go over the magazines.
W: If you need any help, I'll be over at the Reference Desk.
M: Great, thanks a lot.
(20)

A. Searching for reference material.
B. Watching a film of the 1930s'.
C. Writing a course book.
D. Looking for a job in a movie studio.