Passage 2 Questions 6 to 10 are based on the following passage. Friedrich Dobl, a Yugoslav (南斯拉夫人) working in Germany, was annoyed with traffic jams. At long weekends and holiday times when he wanted to get home quickly, he always found himself moving slowly with hundreds of other cars along the crowded foreign workers’ route through Germany and Austria. How easy it all was for police and emergency services! A siren (警报器), a flashing light And like magic everyone was out of the way. Going home from work one night, he passed a garage. And there in front of him was the answer to his problem. An old ambulance was for sale. The red cross had been removed. But not the flashing light, and the siren. He tried the light. It flashed magnificently. He tried the siren. That too sounded impressive. He bought the ambulance and opened up for himself a dream world of motoring. It began early in the morning, all his luggage in the back of the ambulance and the motorway in Germany looking reasonably clear. Soon, as always, a long line of traffic appeared ahead. He switched on the flashing light and set off the siren. Cars swiftly slowed and pulled off the fast lane. Other cars stopped and drivers waved him ahead to an open road all his own. In record time he crossed the border into Austria. His trick was working. Police even waved him through the confusion caused by an accident. But then the Yugoslav made his bad mistake. Until then he had only stopped for petrol. Now he was driving past a real accident, lights flashing, too late to realize that it was not another traffic jam as he assumed. They stopped him, and after hearing the story of his ride across two countries fined him 12.5 pounds. The reason why Dobl decided to buy the ambulance was that ______.