Look, read and complete.(补全下列对话)
Assistant: Can I help you?
Mom: Yes, please. A pair of 1.______
for my son.
Assistant: How about this pair?
Tom: Yes, I like 2.______. It's very pretty.
Mom: How 3.______ are they?
Assistant: They are 4.______
yuan.
Mom: OK. We'll 5.______ them.