听力原文：W: Good morning. Can I help you? M: Yes, please. I'm a new student and I'd like to have some information about the accommodation. W: Right. The university provides two types of accommodation, halls of residence and self-catering accommodation. M: How much does it cost for the self-catering accommodation? W: For a single room, 37.86 pounds per week, that's about 5.41 a day. For a double room, it's 52 per week. M: I'd like the self-catering accommodation. How far is that from the residence to the university? W: It all depends. The residence at 110 Palm Street is about one and a half miles and the Freemen's Common Houses at William Road are about half a mile. M: When do I need to apply? W: Are you an undergraduate or a postgraduate? M: Undergraduate. W: Then you should apply for it as soon as possible, since places in university-owned accommodation are limited and if you don't apply before the end of the month, you are not likely to get a place. M: Could you possibly tell me what to do, if no vacancy is available? W: Yes, you may consider private accommodation. The university runs an Accommodation Information Office and its staff will help you. M: Where's the office? W: In the Students' Union Building. M: Whom can I contact? W: Mr. Underwood. David Underwood, the manager of the Accommodation Information Office. M: Thanks a lot. W: My pleasure. Questions 19 to 22 are based on the conversation you have just heard. 19. What does the conversation mainly tell us? 20. How much does a single room cost per day for the self-catering accommodation? 21. When does a student need to apply if he or she wants a university-owned accommodation? 22. What can we learn from the conversation? (23)