根据上下文,在下面横线处填上适当的词,完成对话。 1. A: Hello! I need a stamp, please. B: (1) are you (2) your letter? A: I'm sending it to Shijiazhuang. (3) (4) is the stamp, please? B: One yuan. A: (5) . 2. A: (6) I see that postcard, please? B: Sure. (7) you are. A: (8) much (9) this postcard? B: One yuan. A: I'll (10) nine, please.