题干
用适当的词语补全对话，每空一词。
Clerk: ____ I help you?
Mary: Yes, please. I want a sweater.
Clerk: What ____ do you want?
Mary: Blue.
Clerk: Here you are.
Mary: How ____ is it?
Clerk: Nine dollars.
Mary: I'll ____ it. Thanks.
Clerk: You're ____.
答案(点此获取答案解析）
Can,color,much,take,welcome
满足约束条件
的最大值和最小值分别为（ ）
