选择下列句子完成下面对话。（共5小题，每小题1分）

A: Good morning. What can I do for you?
B: I want a mobile phone, but I don’t know which one to buy.
A: ________ Which brand do you like best, an HTC, a Nokia or an iPhone 5?
B: I know little about them. Which one sells best?
A: Mm! ________
B: How much is the iPhone 5?
A: ________
B: Oh, they are too expensive. I want the one which is the newest but not too expensive.
A: What about this one? It works well and is very cheap.
B: ________
A: 1,000 yuan.
B: Is there any discount ( 折扣)? How about 800 yuan?
A: ________
B: OK, I’ll take it.