补全对话。
Peter: Oh, David. Please don't put anything on this desk!
David: 1_____?
Peter: Look! This leg is broken.
David: 2_____. When did you find it?
Peter: I found it just now when I was sweeping the floor.
David: Let's tell our teacher about it at once and then someone will repair it.
Peter: No. 3_____.
David: Yourself? Have you learnt to repair a desk?
Peter: Yes. My father is an expert in repairing things. 4_____.
David: Oh, your father taught you. That's great! Do you think 5_____ ourselves?
Peter: Certainly. Let's begin.
