A、A policeman. B、Mr. Blake’s old friend. C、A prison official. D、A runaway criminal. D细节题。文章第二段提到，Blake先生从和中年男子的谈话中得知，这人是一个越狱的逃犯。

One winter evening Mr. Blake was driving in his car along an isolated country road. He had been to New York, in which he had withdrawn 10,000 dollars from the bank.
    He was then going back home with the money, which he had put in his pocket. At the loneliest part of the road a middle-aged man in poor clothes stopped him and asked for a lift. Mr. Blake told him to get into the car and continued on his way. As he talked to the man he learned that he had been in prison for robbery and had escaped out of prison three days ago. Mr. Blake was very worried at the thought of the 10,000 dollars in his pocket.
    Suddenly he saw a police-car and had a clever idea. He had just reached a small town where the speed limit was 40 miles an hour. He pressed down the accelerator and drove the car as fast as it would go. He looked back and saw the police-car had seen this and had begun to chase him. After a mile or so the police-car overtook him and ordered him to stop.
Questions 19 to 22 are based on the passage you have just heard.
19. Where did the story happen?
20. Who was the middle-aged man?
21. How fast could a car drive in the small town mentioned?
22. Why did Mr. Blake drive his car as fast as it could go?