A、4 weeks. B、6 weeks. C、8 weeks. D、10 weeks. B对话中仅出现过一次week，而且前面为six。在听的时候如果对时间比较敏感的话，不难选出B。

M: Hello, Jenny. What are you doing here?
W: Hello, Mark! This is my daughter, Sarah. ’It’s the school holidays, so we’re shopping now. We’re not sure what to do after that.
M: Well, there’s a show for children this afternoon in the library where I work.
W: Oh? What time is it at?
M: It starts at two and finishes at three thirty. It’s only a quarter past one now. Do you think Sarah would like that?
W: How much is a ticket?
M: Well, it’s one pound fifty for adults and seventy -five pence for children. Programmes are twenty- five pence.
W: And does your library run a reading course in the holidays?
M: Yes, and if children under ten, like Sarah, read four books in six weeks, we give them something to take home.
W: What, like a book?
M: Well, this year it’s a pen, but sometimes it’s a book or a school bag. Meet me after the show and I’ll give you more details.
W: Thanks. See you later then.