Question 11 is based on the conversation you have just heard.

听力原文

W: Rays Solar. Lisa speaking. How can I help?

M: Hi, my name is Winston. (8) [I wish to enquire about solar panel installations.]

W: Yes, what would you like to know?

M: Well, my neighbor installed panels on his roof about a year ago in order to power his hot water. He tells me it has saved him over $500 thus far. Does that sound about right to you?

W: Well, I’m not familiar with your neighbor or his particular setup, but that amount is definitely possible. I can tell you that the average four-bedroom house may typically have a roof with 50 square meters of surface area. Four panels on one side of that roof could save a family of four around $300 a year.

M: OK. That sounds about right then. My house is about the size you described, but my neighbor’s is bigger. I’m not sure how many panels he has up there, (9) [but he does have a large family of six.]

W: Are you interested in installing some solar panels on your roof, sir?

M: Yes, I’m considering it.

W: If you wish to come into our office, we could show you the different solutions we offer.

M: OK. I might do that. (10) [But just quickly, if you don’t mind, could you tell me approximately how much a typical installation costs, like, say, four panels?]

W: Prices do vary depending on different factors, but as a rough estimate, it’s around $2,000. But you know, (11) [a typical household will make back that initial investment in about five years.]

M: OK. I see. Thank you.

11. How long will it take a typical household to make back the initial investment?（一般来说一个家庭多长时间能收回成本？）

解析：D。此题可用到视听一致原则作答。录音结尾女士表示，一般来说一家在5年内就能收回成本。D项的About five years在录音中复现，为正确答案。

错项排除：录音中未出现“一年半”这一时间长度，排除A项。录音中出现的数字4指的是在屋顶的一侧安装4块电池板每年可以为一个四口之家节省大约300美元，出现的数字6指的是男士邻居一家总共有六口人，并没有说一个家庭不到四年或大约六年能收回成本，故排除B项和C项。