50. From the passage we can draw a conclusion that forest fires in Alaska, Canada and Siberia may __________.

　　　 A. warm the climate as the supposition goes

　　　 B. allow more snow to reflect more sunlight into space and thus cool the climate

　　　 C. destroy large areas of forests and pollute the far-off sea ice

　　　 D. help to gain more energy rather than release more energy

C

　　　 Kincaid looked at his watch: eight-seventeen. The truck started on the second try, and he backed out, shifted gears, and moved slowly down the alley under hazy sun. Through the streets of Bellingham he went, heading south on Washington 11, running along the coast of Puget Sound for a few miles, then following the highway as it swung east a little before meeting U.S Route 20.

　　　 Turning into the sun, he began the long, winding drive through the Cascades. He liked this country and felt unpressed stopping now and then to make notes about interesting possibilities for future expeditions or to shoot what he called “memory snapshots.” The purpose of these causal photographs was to remind him of places he might want to visit again and approach more seriously. In later afternoon he turned north at Spokane, picking up U.S. Route 2, which would take him halfway across the northern United States to Duluth, Minnesota.

　　　 He wished for the thousandth time in his life that he had a dog ,a golden retriever, maybe ,for travels like this and to keep him company at home. But he was frequently away; overseas much of the time and it would not be fair to the animal .Still ,he thought about it anyway. In a few years he would be getting too old for the hard fieldwork. “I must get a dog then.” He said to himself.

　　　 Drives like this always put him into a sentimental mood. The dog was part of it .Robert Kincaid was alone as it’s possible to be-an only child ,parents both dead , distant relatives who had lost track of him and he of them, no close friends.

　　　 He thought about Marian .She had left him nine years ago after five years of marriage. He was fifty-two now , that would make her just under forty .Marian had dreams of becoming a musician ,a folksinger .She knew all of the Weavers’ songs and sang them pretty well in the coffeehouse of Seattle .When he was home in the old days, he drove her to the shows and sat in the audience while she sang.

　　　 His long absences-two or three months sometimes-were hard on the marriage .He knew that. She was aware of what he did when they decided to get married ,and both of them had a vague(not clear) sense that it could all be handled somehow. It couldn’t when he came from photographing a story in Iceland and ,she was gone . The note read, “Robert ,it didn’t work out ,I left you the Harmony guitar. Stay in touch.”

　　　 He didn’her did she .He3 signed the divorce papers when they arrived a year later and caught a plane for Australia the next day. She had asked for nothing except her freedom.

49. The underlined phrase “soak up” in the last paragraph most probably means ________.

　　　 A. released　　　　　　　　 B. absorbed　　　　　　　 C. created　　　　　　　　 D. distributed

48. Earlier studies about northern forest fires _________.

　　　 A. analyze all aspects of how northern fires influence climate

　　　 B. indicate that forest fires will pollute the atmosphere

　　　 C. suggest that people should take measures to protect environment

　　　 D. suggest that the fires will speed up climate warming

47. The following are all the immediate effects after a forest fire EXCEPT _________.

　　　 A. large amounts of greenhouse gases enter the atmosphere

　　　 B. the levels of ozone which is a type of oxygen increase

　　　 C. snow on the ground mirrors more sunlight back into space

　　　 D. ashes from the fire fall on the ice surface and take in more radiation from the sun

46. According to the new findings, taking steps to prevent northern forest fires may _______.

　　　 A. result in a warming climate

　　　 B. cause the forest fires to occur more frequently

　　　 C. lead to a longer fire season

　　　 D. protect the forests and the environment there

45. Which is the best title for the passage?

　　　 A. Web develops with technology　　　　　　　 B. The present situation of web

　　　 C. Many Americans see little point to web　　 D. It is urgent to promote web service

B

　　　 Against the supposition than forest fires in Alaska, Canada and Siberia warm the climate, scientists have discovered that cooling may occur in areas where burnt trees allow more snow to mirror more sunlight into space.

　　　 This finding suggests that taking steps to prevent northern forest to limit the release of greenhouse gases may warm the climate in northern regions. Usually large fires destroyed forests in these areas over the past decade. Scientists predict that with climate warming, fires may occur more frequently over next several centuries as result of a longer fire season. Sunlight taken in by the earth tends to cause warming, while heat mirrored back into space tends to cause cooling.

　　　 This is the first study to analyze all aspects of how northern fires influence climate. Earlier studies by other scientists have suggested that fire in northern regions speed up climate warming because greenhouse gases from burning trees and plants are released into the atmosphere and thus trap heat.

　　　 Scientists found that right after the fire, large amounts of greenhouse gases entered the atmosphere and caused warming. Ozone(臭氧)levels increased, and ash from the fire fell on far-off sea ice, darkening the surface and causing more radiation from the sun to be taken in. The following spring, however, the land within the area of the fire was brighter than before the fire, because fewer trees covered the ground. Snow on the ground mirrored more sunlight back into space, leading to cooling.

　　　 “We need to find out all possible ways to reduce the growth of greenhouse gases in the atmosphere.” Scientists tracked the change in amount of radiation entering and leaving the climate system as a result of the fire, and found a measurement closely related to the global air temperature. Typically, fire in northern regions occurs in the same area every 80 to 150 years. Scientists, however, found that when fire occurs more frequently, more radiation is lost from the earth and cooling results. Specifically, they determined when fire returns 20 years earlier than predicated, 0.5 watts per square meter of area burned are soaked up by the earth from greenhouse gases, but 0.9 watts per square meter will be sent back into space. The net effect is cooling. Watts are used to measure the rate at which energy is gained or lost from the earth.

44. According to John Barrett, what is the key to attracting more U.S. families to broadband service?

　　　 A. making the Internet look more similar to TV set

　　　 B. applying the Internet more to entertainment

　　　 C. providing more pay-TV programs

　　　 D. chipping away at the core of non-subscribers

43. From the passage we can infer that ________.

　　　 A. It is not an easy job to transform those holdouts into the Internet users

　　　 B. people will adopt dial-up Internet access no more

　　　 C. many Americans enjoy doing e-commerce shopping at home

　　　 D. more than half of the population are using the Internet in 2005

42. Many potential customers refuse to subscribe to the Internet mainly because _________.

　　　 A. they show too much concern about the cost B. they can find little value of it

　　　 C. they do most YouTube-watching at work D. the Internet doesn’t reach their homes

41. What does the underlined word “holdouts” in the first paragraph most probably mean?

　　　 A. some American families

　　　 B. those who hold out one’s opinions

　　　 C. those who have been surveyed

　　　 D. those who still haven’t access to the Internet currently