（A）
Suddenly another thought went through Kate’s mind like an electric shock. An express train was due to go past about thirty minutes later. If it were not stopped, that long train, full of passengers, would fall into the stream. “Someone must go to the station and warn the station-master,” Kate thought. But who was to go? She would have to go herself. There was no one else.
In wind and rain she started on her difficult way. Soon she was at the bridge that crossed the Des Moines River, a bridge also built of wood, just like the bridge across Honey Creek. The storm had not washed this away, but there was no footpath across it. She would have to cross it by stepping from sleeper(枕木) to sleeper. With great care she began the dangerous crossing, sometimes on her hands and knees, hardly daring to look down between the sleepers into the wild flood waters below. If she should slip, she would fall between the sleepers, into the rapidly flowing stream.
At last - she never knew how long it had taken her - she felt solid ground under her feet. But there was no time to rest. She still had to run more than half a mile and had only a few minutes left. Unless she reached the station before the express did, many, many lives would be lost.
She did reach the station just as the train came into sight. Fortunately the station-master was standing outside. “The bridge is down! Stop the train! Oh, please stop it!” Kate shouted breathlessly.
The station-master went pale. He rushed into the station building and came back with a signal light. He waved the red light as the train came into the station. It was not a second too early.
21. What did Kate decide to do?
A. Stop the express train. B. Check the signal light.
C. Meet the passengers. D. Visit the station-master
22. Which of the following words best describes Kate’s journey?
A. Fruitless. B. Well-planned. C. Pleasant. D. Risky.
23. What can we learn from the last paragraph?
A. The station-master was unhealthy. B. Kate's efforts paid off.
C. The train arrived later than usual. D. The train failed to stop.
