选择合适的选项补全对话。
A. How much are they?
B. Can I help you?
C. OK. We'll take them.
D. What size ?
E. Yes. But I like the blue pair.
A:____
B: Yes. A pair of shoes for my son.
A:____
B: Size6.
A: How about this pair?
B: Are they nice，John?
C:____
B: Are the blue ones all right?
C: Yes. they are.
B:____
A: They are 40 yuan.
B:____
