Mum: It's a sunny day. Let's go shopping(购物).
Chen Jie: Great!
Assistant: Can I help you?
Chen Jie: Yes. These orange shoes are nice. Can I try them on? Size 33, please.
Assistant: Sure. Here you are. Are they OK?
Chen Jie: Yes, they are just right.
Mum: How much are they?
Assistant: They are eighty yuan. But they are on sale today. They're only forty yuan.
Mum: So cheap. We'll take them. How about this red cap? Is it on sale today?
Assistant: No. But it's not expensive. It's only fifteen yuan.
Chen Jie: Amy's birthday is coming. Let's buy two caps—one for Amy and one for me.
Mum: OK. The shoes and two caps, please.
Assistant: OK. Here you are.
They're yuan.(用数字回答)