A、She doesn’t know how to use the search engine. B、The computer doesn’t work after she types into the keywords. C、The books have

W: Hi,can you help me? I’ve got to write an essay on electrical distribution and transmission systems,but I can’t find any suitable books in the engineering section on level three.
M: Have you used the library search engine?
W: You mean typing the keywords into the computer? Yes, I’ve done that. (19) A couple of books come up but they’re not on the shelves. Someone’s taken them out.
M: Well,I can put a reserve on them so that when the person brings them back to the library,we can put them on one side for you. Do you want to do that?
W: Mmm,I don’t know. I suppose so,but ideally,I’d like to get started on my essay sooner rather than later.
M: Well,there are some other options. Have you used the journal database?
W: No,what’s that?
M: Didn’t you go on a library induction tour in the first week of term?
W: No,I was ill that week.
M: Well, I recommend you do that. You’ll learn a lot of useful things. Anyway, I’ll just quickly show you how to use the journal database. If you go onto the library homepage on the computer, and click on databases in the top right hand corner, (20) it takes you to all the e-journals that we have access to here at the university library. You can use the search engine to find journals that are related to your keywords. (20) See, if I type in electrical transmission, you get over five thousand articles.
W: Wow.
M: So, that’s a good place to start. Meanwhile, (21) you can always go and talk to your subject librarian. The person for Electrical Engineering is Mark Taylor. His office is on level four.
W: OK,thank you.
19. Why can’t the woman find the books she wants?
20. What does the man say about the journal database?
21. What does the man suggest the woman do in the end?