【正确答案】 C

【答案解析】[听力原文]11-13 W: I want to mail this letter overseas. M: OK, Ma' am. I'll have to weigh it first. All right, it' s not over weight. That' s 5.5 yuan for overseas mail. W: That' s not expensive. How long does it take for a letter to get to the U. S. ? M: It all depends. It usually takes four or five days. W: That' s wonderful. It used to take more than a week when I was staying here six years ago. Well, I want to register it. M: All right. It' s probably take a little longer to get there though. W: Yes, I know. Well, please let me have a post office box. M: That' s OK. Fill out this form, please. W: How much is the rent per month? M: It is 100 yuan per year. W: Here is the form and money. M: OK. Here is the key for you. The number is on it. Any more requests? W: No, Thank you.