口语交际：根据对话内容与上下文，用适当的词或句子补全对话，使对话完整通顺。
Mrs Brown =A Salesgirl =B
A: Good morning!
B: Good morning! ①________?
A: ②________. I want to buy a sweater.
B: Come this way. Here are sweaters.
A: ③________ is this white one?
B: 49 dollars (美元).
A: How much is it in Chinese money?
B: About 400 yuan.
A: ④________
B: But good things always cost (值) much .
A: I know that. And ⑤________ that blue one?
B: That's cheap (便宜). It's only 100 yuan.
A: Ok. I'll take it.