Niu Naitang: Mum, let's buy(买) some fruit.
Mum: Do you like bananas?
Niu Naitang: No, I don't. I like grapes.
Mum: What about some mangoes?
Niu Naitang: Yes, please.
Mum: OK, some mangoes and some grapes.
Woman: Here you are. Twelve yuan.
Mum: They are cheap(便宜的) .