A、Before the end of the month. B、At the beginning of the year. C、Next month. D、Any time. A选项表明，本题考查时间。对话中女士提到if you don’t apply

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?