A、There are too many people living there. B、The cost of living there is relatively high. C、It has frequent natural disasters. D、

M: Hello, Miss Lin. So glad to see you!
W: Oh, no, you aren’t. I’ve been here hundreds of times for the visa, so you couldn’t possibly be glad to see me again.
M: But I’m really glad to see you this morning. I was just going to ring you up to let you know the visa has been granted at last.
W: Really? I can hardly believe my ears! Do you realize I’ve been waiting for nearly 6 months by now?
M: That’s not very long, compared with the time it took many other visa applicants.
W: This, I suppose, is British efficiency.
M: Let’s not put it that way, please!
W: To tell you the truth, if I were somebody who wanted to stay in another country for good, I certainly wouldn’t choose Britain.
M: Why not?
W: As far as I know, the living cost there is very high, compared with that in America, Switzerland. Sweden and many other western countries.
M: That, I must admit, is true.
W: Besides, Britain is well-known for its bad weather. I hear the sun hardly ever shines there.
M: Yes, we have maritime climate. It can’t be helped. But what puzzles me now is why you have applied for a British visa after all?
W: The answer is quite simple. I happen to be a student of English, and I want to get an MA degree. For that purpose I’ve decided to go to the University of London, even if it does rain every day in England.
M: I see, no wonder you speak such fluent English. Here’s your passport and the visa is on this page. Now you can go and get your health certificate.
19. Why did the man want to call the woman in the morning?
20. What is the disadvantage of Britain compared with other western countries?
21. Why did the woman go to Britain?