Listen to a conversation between two students.
Man：Hey. Jill. What's on your mind?
Woman：I'm trying to decide what to do about the paper for my history class. A big part of the assignment is working with original historical documents.
Man：Originals.
Woman：Yeah. You know, our library has all kinds of records and books dating back hundreds of years.
Man：Amazing! So is there a problem?
Woman：Uh-huh. The librarian just told me that the documents I was planning to use aren't available right now. They are old newspapers and they were in pretty bad shape, so the library sent them out for repairs, like, restoration work.
Man：So you can't use them.
Woman：No. They say they won't be available for at least another two weeks. So I can't work on my paper.
Man：Well, can you change what you are writing about? You know, choose a topic that doesn't involve those documents.
Woman：I could. There are plenty of historical topics. Then I could really get working on the paper right away, but...
Man：But what?
Woman：Well, I've already done a bunch of research on my current topic. I've collected a lot of information and I wouldn't be able to use any of it if I changed my topic.
Man：Well, when did you say the documents, the old newspapers, will be available?
Woman：The librarian said two weeks.
Man：So you could just postpone working on the paper, wait until they are available.
Woman：Possibly. Unfortunately that would mean doing major work on my paper in the last week of the school term, when I will be working on a lot of other things. If I change the topic, I can really work on the paper right away.