American like to visit the national parks. In 1996, over 250,000,000 people visited areas run by the National Park Service. Experts predict that by 2010, 500,000,000 people per year will visit the parks. As a result, people are trying to think of ways to protect the parks from the crowds. The crowding of the parks has caused several problems. One is that there is not enough space for all of the people who want to use the parks. To cope with this problem, national parks may require reservations （预约）months in advance for some spots. The Park Service may also raise entrance fees at these places. Another problem caused by increased park use is pollution. Some garbage and waste can be cleaned up, and the cleanup can be paid for by increased entrance fees. To cut down on noise pollution and air pollution, officials may decrease（减少） the number of cars allowed in parks. If this happens, people may use buses to travel around the parks. Officials may also limit（限制） the use of jet-skis, snowmobiles (摩托雪橇), motorboats, and sightseeing helicopters and planes. The parks are also threatened by development that is going on around them. For example, around Yellow Stone Park, many motels (汽车旅馆), golf courses, resorts, and other tourist attractions have been built. Some of these developments affect areas that are used by animals. People will have to learn to agree about ways to protect the parks. If they do not, there will soon be no reason to visit these national treasures. 小题1: By 2010, the number of visitors will rise by ______. A．250 million B．500 million C．2.5 billion D．5 billion 小题2:If you want to visit the national parks, you may have to _____ in the future. A．pay less than before B．stay there for months C．book the ticket before months D．fill in a form to apply for the ticket 小题3: Entrance fees may be increased _______. A．just for the benefit of the National Park Service B．either to limit the number of visitors or to pay for the cleaner C．not only to protect the animals but to reduce the noise pollution D．merely for the development of the national parks 小题4:What does the underlined sentence in the passage mean? A．People are not supposed to visit the national parks for fear that they will harm the animals. B．Only if more man-made tourist attractions are built will more people visit the parks. C．It is reasonable to keep the balance between the development of the parks and the reserve. D．People will not visit the national parks since there are no golf courses and resorts. 小题5:What can be inferred from the passage? A．High fees may probably keep some people out of parks. B．Helicopters and planes will not be used in parks any longer. C．The bus will become the only tool in parks with the purpose of pollution reduction. D．The National Park Service welcomes as many visitors as possible.