A、Because he is interested in the subject. B、Because he has already written a paper on it. C、Because he does not know anything a

M: Good morning, Betty, do you know what the assignment is for our term paper in history?
F: Sure, Joha But, weren’t you in class on Monday? That’s when it was given out.
M: No, I missed that class. Was there a handout?
F: No, the instructor just wrote the assignment on the board.
M: Could I copy the assignment from your notes?
F: You could, if I had copied it all down; but I just wrote down the part that I wanted.
M: Oh, no.
F: You see, there were four choices of topics for the term paper; but, when I saw them, I knew which one I wanted so I didn’t copy the others down.
M: Can you remember any of the others?
F: Let’s see. There was one about World War I, something about it, but I don’t remember what, and there was one called "the idea of progress in the nineteenth century. "
M: And what was the last one?
F: I can’t remember. My mind is a complete blank. Maybe you can ask someone else.
M: Yes, I will. Anyway, those are certainly broad topics.
F: Yes, but you can focus on a special area within them. Which one would you take?
M: Of course, I don’t know what the last one is, but of these three, I think I’d take "the idea of progress. "
F; That’s very abstract.
M: Yes, but it is one of my interests and I’ve read a lot on the subject. I’ve never written a term paper on it though.
F: Me neither. I haven’t even read about it. Are you going to class on Wednesday?
M: Yes.
F: Maybe he’ll write it on the board again.
M: I hope so. Good luck with your paper.
F: Same to you.
Question No. 19 How many topics did the teacher give for the term paper?
Question No. 20 How was the assignment given out by the instructor?
Question No. 21 Why can’t John copy the assignment from the Betty’s notes?
Question No. 22 Why does John choose to write on the "idea of progress in the nineteenth century"?