OFFICIAL24 What are two possible reasons that the speakers consider for why the man cannot find the book?

[00:00.00]NARRATOR: Listen to a conversation between a student and a clerk in the bookstore. [00:11.18]MALE STUDENT: Hi. Can you tell me where to find New Kind of Science, by, uh, by Stephen Wolfram? [00:17.82]FEMALE CLERK: OK
[00:18.79]MALE STUDENT: ...uh, I couldn't find it
[00:20.81]FEMALE CLERK: OK. Let me look it up on the computer for you. [00:23.17]Who would you say the author was?
[00:24.99]MALE STUDENT: It's a Stephen Wolfram.
[00:27.35]FEMALE CLERK: OK. Let's see... Hmm... no, it's not coming up. Hmm..,. I am not seeing it [00:34.00]MALE STUDENT: Um...hmm.
[00:35.10]FEMALE CLERK: This is for a class here at the university, right?
[00:37.96]MALE STUDENT: Yeah, it's assigned reading for a class that I am taking.
[00:41.13]FEMALE CLERK: It's for the semester, right?[00:42.74]You are not buying it in advance for next year or anything.
[00:45.80]MALE STUDENT: No, no. It's for a class I am taking now. [00:48.17]FEMALE CLERK: Hmm...
[00:49.00]MALE STUDENT: Oh, but you know what? [00:50.33] It's for a graduate class. [00:52.24]Would that maybe make a difference? [00:54.42]I mean, I'm an undergrad, but I'm just, I'm just taking this one class in the graduate department, so maybe?[01:00.29]FEMALE CLERK: No, no, I don't think that's it. [01:02.10] That shouldn't make any difference, [01:03.77]but, mh, let me see...maybe it's just...it could be that whoever entered it misspelled the title or the author's name, so I can't find it on the computer, and I can't tell if it's sold out. [01:15.57]But if it is sold out, we would probably be getting a new shipment within about a week or so.[01:20.92]MALE STUDENT: OK, well I was hoping to get it sooner, 'cause like we already have assignments and, you know. I mean I guess I could get it from the library?[01:30.93]FEMALE CLERK: Right, of course. [01:32.36] But I'm trying to check; [01:33.66]if we've ordered more, then that backorder information should be in the computer too. [01:38.68]Let's see... backorder-Wolfram-Steven...no...I'm still not seeing it. [01:45.78]I'm sorry, [01:46.87]we just don't seem to carry it.
[01:48.23]MALE STUDENT: Uh-huh.
[01:49.42]FEMALE CLERK: This is odd though.[01:50.31]What is...what's your professor's name? [01:53.19]I could try searching for his or her classes in the database. [01:56.45]That might help
[01:57.30]MALE STUDENT: Um...OK. It's professor Kayne.
[01:59.75]FEMALE CLERK: K-A-N-E? [02:01.71]MALE STUDENT: No. It's professor Kayne, K-A-Y-N-E.[02:05.31]He's in the computer science department. [02:07.12]FEMALE CLERK: Oh. It's for a computer science course, is it?
[02:10.03]MALE STUDENT: Yeah. [02:10.69]FEMALE CLERK: Well, that must be it. [02:12.00]Computer science books are sold across the street in the computer store.
[02:15.42]MALE STUDENT: Oh, are there signs up anywhere?
[02:18.71]FEMALE CLERK: I don't know. [02:19.36]MALE STUDENT: Maybe they should put some up.[02:21.32]It could have save us both some time. [02:23.10]FEMALE CLERK: Yeah. Well, anyway, I'll bet that's the problem. [02:25.97]Check across the street. [02:27.70]I'll bet they have it. [02:28.72]But if not, come back, and I'll help you find it somewhere else. [02:31.64]I can call around to see if other bookstores might have it. OK?
[02:34.83]MALE STUDENT: OK. Thanks a lot. Bye
[02:36.81]FEMALE CLERK: Bye