2009年6月英语四级听力部分模拟题(五)

　　Section B
　　Directions: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A)， B)， C) and D). Then mark the corresponding letter on Answer Sheet 2 with a single line through the centre。
　　Passage One
　　You can find it orbiting Earth, floating in space, or sitting on Venus, Mars, and the Moon. No, it’s not a space---it’s space trash! Space trash, often called space debris, is any man-made object that no longer serves a useful purpose. More than 4,000 satellites have been launched into space since 1957. All that activity has led to large amounts of space trash。
　　Nicholas Johnson, a chief NASA scientist and program manager for orbital debris, monitors more than 1,300 objects that are at least three to four inches wide. Of those objects, only 600 to 700 are still in use. The oldest piece of space trash is Vanguard 1, the second satellite that the United States launched. Vanguard 1 has been in space since March 1958。
　　Space trash moves very quickly. According to Johnson, speeds may reach 18,000 miles an hour. Because the trash moves so quickly, even very small pieces can cause damage. Today the trash causes only minor damage to satellites. That’s largely because of measures that NASA and other countries’ space programs have taken. For example, making sure that no fuel is left on satellites limits the amount of explosions that can send trash hurtling through space。
　　Questions 26 to 28 are based on the passage you have just heard。
　　26. What is space trash?
　　27. According to a chief NASA scientist, how many man-made objects that are at least three inches wide are there in the space, which are no longer in use?
　　28. Why is space trash dangerous?
　　Passage Two
　　People all over the world have begun to realize the countless possibilities of a new freedom: Leisure. This is especially true in countries with a highly-developed technology. Modern technology, automation, shorter working days, long weekends, earlier retirement, and better health have given people much more free time than they have ever had before. Modern agricultural equipment has liberated the farmer from long hours of hard labor; automation has had a revolutionary effect on business and industry; and modern household appliances have freed women from many tiresome and time-consuming chores. Only students have not gained leisure time in this day and age. They have to study longer and harder than ever before in order to keep up with our rapidly changing world and prepare them for the future. But then, the life of a student has always been, and probably always will be, one of much effort and little free time。
　　In the early days of American history, the value of work was a dominant concept in the American way of life. Now, almost everyone recognizes the necessity and value of relaxation and recreation. People are supposed to work in order to support themselves and their families and to contribute to society. However, they also enjoy many other activities and profit from them。
　　Questions 29 to 31 are based on the passage you have just heard。
　　29. What have people all over the world begun to recognize?
　　30. Who has been liberated from long hours of hard work?
　　31. When was the value of work a major concept in American life?
　　Passage Three
　　Until recently, a tomato was just a tomato. But now scientists have begun to change the genes of plants in laboratories, so it is not as easy to know when tomatoes are pure tomatoes. That is true with many other vegetables and fruits。
　　Genetic engineering is the process of taking genes from one plant or animal and putting them into another plant or animal. Scientists use the process to increase the nutrients a food contains. However, this new genetic engineering technology has raised a lot of questions。
　　The United States Food and Drug Administration is responsible for deciding how foods must be described when they are sold. The FDA says people who buy human foods produced by new kinds of plants must be told if there are any safety problems. It also says people must be told what nutrients the foods contain。
　　There are, however, times when more information about a new food product would be helpful. Some foods are not a safety threat, but do affect people in unusual ways. After eating the food, they may develop red spots on their skin, or have trouble breathing or have a sick stomach。