Question 13 is based on the conversation you have just heard.

M:You are going to wear out the computer's keyboard.

W:Oh. Hi.

M:Do you have any idea what time it is?

W:About 10:00 or 10：30?

M:It's nearly midnight.

W:Really? I didn't know it was so late.

M: (12) Don't you have an early class to teach tomorrow morning?

W: (12) Yes, at 7 o'clock. My commuter class-the students who go to work right after their lesson.

M:Then you ought to go to bed. What are you writing anyway?

W:An article I hope I can sell.

M:Oh, another of your newspaper pieces. What's this one about?

W:Do you remember that trip I took last month?

M:The one up to the Amazon?

W: (13) Well, that's what I'm writing about. The new highway and the changes it's making in the Amazon valley.

M:It should be interesting.

W:It is. I guess that's why I forgot all about the time.

M:How many articles have you sold now?

W:About a dozen so far.

M:What kind of newspapers are they?

W: (14) The papers that carry a lot of foreign news. They usually appear in the big Sunday editions where they need a lot of background stories to help fill off the space between the ads.

M:Is there any future in it?

W:I hope so. (15) There is a chance I may sell this article to a news service.

M:Then your story would be published in several papers, wouldn't it?

W:That's the idea. And it might even be able to do other stories on a regular basis.

M:That would be great.

(13). What is the woman writing about?

解析：C。本题为细节题。问题为：这个女士在写些什么？根据原文“Well, that's what I'm writing about. The new highway and the changes it's making in the Amazon valley.”可知女士在写新高速公路和它对亚马逊山谷产生的改变，故正确答案选C。