听力原文：W: Mr. Atkins, Would you please tell the court what you were doing when the accident happened and what you saw? M: Yes, I was driving home from work. It was about 5:15, and there was a blue car in front of me. We were both driving along Harbor Road when a small white Ford suddenly shot out of a side road. It shot right in front of the blue car. The driver tried to stop, but it was impossible. He ran into the white Ford. W: I see. Now, how fast was the car in front of you going when the accident happened? M: The blue car? 30 miles an hour. Certainly no more than that. W: And the white Ford shot out without any warning? M: Yes, that's right. W: Then, how can you be sure the blue car was only doing 30? M: Because I was only doing 30, and the blue car wasn't going any faster than I was. W: Are you sure of that? M: Yes, I am. I'm positive. W: How can you be so positive, Mr. Atkins? Were you looking at your speedometer when the accident happened? M: Of course not. I was looking at the road ahead. That's how I managed to see the accident! W: Well, if you weren't looking at your speedometer, how can you possibly be sure how fast you were going? M: Because I never go faster than 30 on that road. (20)