—Why is the man running in the street?
—He _____ for exercise.

根据语境，填写适当的词语或句子补全对话。
A: Look at the man running down the street. Why do you think he is running?
B: He could be running for exercise.
A: No.  He might be running to _    1 ___. He is wearing a suit.
B: But there is no bus on this road.  Buses are not       2       to run here.
A: Oh! Maybe he is going to be late and running to work.
B: I don't think so.  He _    3  __ scared.
A: Yes.  You are right.  Look! What's that in the sky?
B: It _    4  __ a UFO.  And it's landing.
A: Look at that woman with a camera.
B: She must be a reporter from the TV news.
A: No.  Look at those other people.  They are actors.  Oh, I see.       5      .