A、A druggist’s suggestion. B、An article. C、An advertisement. D、A sales clerk’s comment. B通过上题的分析，对话是由女士所读的一篇文章引起的，提及了人们在药店买药所用的时

W: I just read a curious fact. Did you know that people who spend less than ten minutes in a drugstore are five times more likely to make a purchase than those who spend half an hourthere?
M: I saw that article, too. But I think, if someone runs into a drugstore for ten minutes, it’s usuallyto make a specific purchase.
W: And someone who spends more time there may just be looking.
M: Exactly. Haven’t you ever gone into a store thinking that you’d like to buy something, andthen talk yourself out of it?
W: Yes, I have, especially when I thought I would get it for less elsewhere, or I really didn’t need
it after all.
M: Exactly. But if you run into the store, wanting to buy something specific and have verylittle time, you pick it up, pay for it immediately and then leave.
W: That’s true. Maybe we should learn a lesson from that. Take your time and you’ll spendless money.
M: I doubt if that would be true in all stores, though. In a department store, for instance, youmay see a sweater or something you never intended to buy, and buy it because you have timeto look around.
Questions 19 to 22 are based on the conversation you have just heard.
19. What is the main topic of the conversation?
20. What started the conversation?
21. What fact has the man and the woman learned about the drugstore?
22. What does the man say about people who shop quickly?