Passage One
　　Most people know what a hotdog is. It's a sausage in a roll. But do you know why it's called a hotdog? Well, the long red sausage which goes into a hotdog is called Frankfurter. It got its name from the German town Frankfurt. The sausages were very popular, but hot frankfurters were difficult to sell in crowds. One man, Harry Stevens, had the job of feeding the crowds in baseball games. He had an idea, why not put the Frankfurters in long hot bread rolls? This made them easy to sell. The red hots had a hot and attractive taste, and became very popular. But in 1903, an American cartoonist drew a long German sausage dog in place of the Frankfurter. So an Frankfurter in a roll soon became known as a hotdog. It was a joke, but some people really thought the sausages contained dog meat. For a while, sales of hotdogs failed, but not for long.

　　Questions 11to 13 are based on the passage you have just heard.
　　11. What is a Frankfurter?
　　12. What was Harry Stevens' job?
　　13. Why did the sales of hotdogs decrease for some time?

　　Passage Two
　　We all scream for water when thirsty. But do you know in very hot, dry weather, plants also make faint sounds-as if they are crying out for help? You see, in a plant's stem, there are hundreds of water pipes that bring water and minerals from the soil all the way up to the leaves. As the ground turns dry, it becomes harder and harder for the plants to do this. In severe droughts, plants have to fight to pull out any water available. Scientist Robert Winter has found out that when it is really bad, their water pipes snap from the tension like rubber bants. When that happens, the whole plant vibrates a little. The snapping pipes make noises 10,000 times more quiet than a whisper. Robert knows that healthy, well-watered plants are quiet. He also knows that many insects prefer attacking dry plants rather than healthy plants. How do the insects know which are healthy plants and which are not? Robert thinks that the insects may listen for the plants that cry. And then they may buzz in to kill. To test this theory, Robert is using a device that can imitate plant cries. He attaches it to a quiet, healthy plant so that the plant sounds thirsty. Then he watches the insects to see if they attack more often than usual. If he is right, scientist could use the insects' ability against them. They could build traps that imitate crying plants, so that when the insects buzz in to eat, They won't buzz out.

　　Questions 14 to 16 are based on the passage you have just heard.
　　14. What do plants do when they are thirsty?
　　15. What plants do many insects tend to attack?
　　16. What could scientists do if Robert's theory proves to be true?

　　Passage Three
　　People enjoy taking trips. But what are the reasons they leave home? One reason is for education. People travel because they want to broaden their horizons, to learn about other people and other places. They are curious about other cultures. When people are tourists, they get a quick look at different ways of living. Even a short look at another kind of lifestyle is an important lesson. On a trip, a person can learn directly-by visiting museums and historic spots. What does a tourist learn who sees the art museums, visits the historical palaces, and other scenic spots in Paris, and shops along the River Seine? He gets a vivid picture-a real-life-one of the French people. He learns about their attitudes: how they feel about business, beauty, and history. What about the tourist to goes to HongKong? Does he get the same information that he could get from a book? He might read that HongKong is crowded, that there is less than 200 square meters of space for each person. But seeing and feeling the lack of space will impress him much more. He might read that there are nearly 200 vehicles for every kilometer of roadway, but the sight of so many vehicles parked along the roadside will be a much more vivid lesson. The tourist to HongKong will never forget the contrasts-the straight verticle lines of the tall modern buildings and the moving lines of boats that people live in.

　　Questions 17 to 20 are based on the passage you have just heard.
　　17. Why do people leave home to travel according to the passage?
　　18. What do we learn from the passage about Paris?
　　19. What impression will a tourist get of HongKong?
　　20. What does the passage tell us about travelling?