A、30 percent off. B、35 percent off. C、20 percent off. D、25 percent off. A本题的问题关键词是discount。对话中提到这些裤子买的时候是thirty percent off，也就是

M: May I help you?
W: Yes, I would like to return these trousers.
M: All right. Do you have your receipt?
W: Yes, here it is. I bought them last week.
M: And why are you returning them?
W: I bought them to go with a blouse of mine. But they don’t really match.
M: I see. Oh, wait, madam, I’m sorry. These trousers were on sales.
W: Yes, they were thirty percent off.
M: I’m sorry, but we don’t allow returns on sale items.
W: I know many stores have that policy. But I have returned sale items here before.
M: I’m sorry, but we usually don’t do it. It is our policy.
W: I just bought these trousers a week ago. And I am a regular customer here. Can you make an exception this time?
M: Well. Let me talk to the manager for a moment.
(10 minutes later)
M: Madam, the manager says I can do it this time.
W: Good, I’m a regular customer here. I am glad you can make an exception for me.
M: Please show me your receipt again.
W: Here it is.
8. What’s the discount of the trousers?
9. Why did the customer buy the trousers?
10. What’s the policy of that store?