大学英语六级-90及答案解析.doc

1、大学英语六级-90 及答案解析(总分：543.00，做题时间：90 分钟)一、BPart Writing(总题数：1，分数：106.00)1.1. 出国留学的好处；2. 出国留学的弊端；3. 结论和你的观点。BThe Advantages and Disadvantages of Studying Abroad/B（分数：106.00）_二、BPart Reading (总题数：1，分数：10.00)BAliens/BAre there other forms of life in the universe? The scientific search for extraterrestrial

2、 (ET) life forms has been bolstered by two recent discoveries. First, the discovery of life forms in exotic environments on Earth indicates that life is very hearty and can adapt to the strangest and most hostile environments. Second, astronomers found planets orbiting stars besides our sunover 50 e

3、xtrasolar planets have been discovered as of 2001. Are there alien life forms on any of these planets?If alien life does exist, what might it be like? Would it be simple forms of life such as bacteria, viruses or algae, or more advanced, multi-cellular creatures, perhaps even intelligent beings? Wou

4、ld aliens be animals, plants or have characteristics of both? Would they have arms and legs and walk upright as we do? Would they depend upon vision as their primary sense or use another way to gather information about their surroundings? Would they “breathe“ oxygen or some other gas? BGreetings, Ca

5、rbon-based Bipeds(两足动物) !/BMost of us picture alien life the way its portrayed in movies, where aliens are commonly depicted as human-like forms because they use actors either to play the roles directly in make up or to be models for computer-generated animation. Also, audiences relate to human-like

6、 aliens better than to more exotic, monster like. However, the human body plan bilateral symmetry with onehead, two legs and two armsstems from when early animals such as lizard, crocodile, or dinosaur colonized the Earths land masses, and it seems unlikely that such a shape would evolve on an alien

7、 world. So, lets forget Hollywood for the moment and look closely at the real science of astrobiology.Astrobiology is the scientific study of life in the universe. Astrobiologists seek to understand (among other things) how life arose and evolved on Earth, what governs the way life is organized and

8、what makes a planet habitable.Astrobiology combines the disciplines of biology, chemistry, physics, geology and astronomy. Often, astrobiologists must use the information learned about life on Earth as a guide for studying life elsewhere. Lets examine some of the unusual things that we have learned

9、from life on Earth: BLife in the Extreme/BUp until about 30 years ago, it was believed that all life on Earth was dependent upon energy from the sun. Furthermore, it was thought that you would probably not find life where temperatures were extremely hot, like in geysers or hot springs, or extremely

10、cold, like in the Antarctic desert.These ideas changed when oceanographers explored hydrothermal vents, openings in the ocean floor where extremely hot, mineral-rich water erupts from the crust. Hydrothermal vents are located several miles below the surface, on the ocean floor, where the surrounding

11、 water is at or near freezing, it is absolutely dark and the pressure is high. In organized communities around the bases of these vents, called black smokers, scientists found clams, crabs and exotic, giant tubeworms measuring 6 feet (2 meters) long. The water coming out of these vents is 230 to 662

12、 degrees Fahrenheit (110 to 350 degrees Celsius).How can these animals survive so far from the sunlight, under these extreme conditions? In the water, scientists found species of bacteria that split hydrogen sulfide(硫化物)from the water to get energy to make organic compounds. The tubeworms have bacte

13、ria in their tissues that help them derive energy from the water. The clams feed on the bacteria, and the crabs feed on the tubeworms.The discovery of hydrothermal-vent communities showed that it is possible for life to evolve in places without light from the sun, and in other worlds without suffici

14、ent light from the parent star. In view of the discovery of hydrothermal vents, it may be possible that life exists on Europa, an icy moon of Jupiter, which scientists believe has a water ocean beneath its icy crust.Life has been found in other extreme environments as well. Scientists discovered mic

15、rocolonies of lichens (地衣)called cryptoendoliths in rock samples of the Antarctic desert, where temperatures often drop to 100 degrees below zero and there is little or no liquid water. In contrast, thermophilic (heat-loving) bacteria have been found in hot springs where temperatures exceed the boil

16、ing point of water.If life can evolve in extreme environments on Earth, it seems possible that life may exist in the extreme environments of other worlds such as mars.BSpeculation: What Might Aliens be Like?/BSince no extraterrestrial life forms have been conclusively discovered, alien physiology li

17、es in the realm of our imagination. Science-fiction authors, especially the “hard“ ones who try to adhere strictly to real science, have been doing this for years. They first design or build a world, carefully working out its physical, astronomical and ecological characteristics. Next, they work out

18、 what type of aliens could exist in that world. An example of one such world-building exercise can be found at the Epona Project, where several science-fiction writers came together to create a world called Epona, complete with planetary, geological and ecological data. One artist, Steven Hanly, cre

19、ated Epona creatures.For his novel “Mission of Gravity,“ Hal Clement created a world called Mesklin that circles a double star. Mesklin rotates once every eighteen minutes and has a flattened shape caused by its rotation. The gravity of Mesklin ranges from three times Earths gravity, at the equator,

20、 to seven hundred times at the poles. Mesklin has a hydrogen atmosphere and methane(甲烷)oceans. Mesklinites, one of the planets life forms, are small, centipede-like creatures made of an insect skeletal protein called chitin. They have 18 pairs of legs that end in sucker-like feet, forward pinchers f

21、or grasping, a strong circulatory system and absorb hydrogen right through their shells. They are immensely stronga result of living on a high-gravity world, yet they have a fear of being picked up because a fall from a small height could be fatal on such high gravity.Previously weve envisioned an a

22、lien world and alien life forms. In our world, the planet orbits a bright star. Only 10 percent of the world is covered with surface water, but throughout the land mass there are pockets of water that collect under the sands from the sparse rainfall. The enyironment is hot and arid and the sunshine

23、is bright. The planet is massive and has gravity that is one-hundred times stronger than that of Earth. The atmosphere is an Earth-like air mixture of helium, oxygen and carbon dioxide.The two alien life forms that we envision for this world are animalsmobile predators that live around the planets f

24、ew small bodies of surface water. Both aliens are short, about 1 foot (30 centimeters) tall, with thick limbs to support their weight against the immense gravity. Both have thick coverings or skins to minimize evaporation and conserve water. To gather information, one relies primarily on vision, whi

25、le the other uses chemical senses (taste and smell).The Lashlarm is our first alien predator. It looks like a walking toilet bowl. The mouth portion is supported by three stalky legs connected to a flat base. Underneath the base are many scales, so the base glides across the surface of the sand much

26、 like a snake moves along the ground. It has several sensory appendages that allow it to locate prey by chemical means. It hunts near the small bodies of surface water, feeling along the waters edge and tasting the sand and water for other animals. Upon locating prey, the Lashlarm crouches down and

27、glides up to it. The Lashlarm then opens its large mouth and springs down upon the prey, swallowing it whole.The Nirba is slightly larger than the Lashlarm. It lives in the water, near the edge, much like a crocodile or alligator but is not fully aquatic(水栖的). The Nirba comes out to prey on other an

28、imals that come down to the water, particularly the Lashlarm. It has a large head with nostrils located on top of its nose so it can breathe while mostly submerged. The Nirba has thick skin, to prevent dehydration while out of the water in the hot sun, and big, muscular front legs with large claws f

29、or killing its prey. A long tail helps it swim in the water, and the “arrowhead“ end assists in hunting and territorial defense.（分数：10.00）(1).There may be other life forms in the universe because over 50 extrasolar planets were discovered in 2001.（分数：1.00）填空项 1:_(2).In some movies where aliens are c

30、reated as the enemy of human, they are usually monster-like creatures.（分数：1.00）填空项 1:_(3).Astrobiology, a branch science combining many other branches, studies the life on Earth.（分数：1.00）填空项 1:_(4).We used to believe that life could not exist under extremely hot or cold environment.（分数：1.00）填空项 1:_(

31、5).The animals living in extreme oceanic environments have to feed on certain bacteria that help them get energy from_.（分数：1.00）填空项 1:_(6).Because people have not convincingly found any alien life forms, such forms are just our_.（分数：1.00）填空项 1:_(7).For creatures living under high-gravity condition i

32、n Hal Clements novel, even a fall from a notvery-high place can be_.（分数：1.00）填空项 1:_(8).In the extremely hot and dry environment, creatures are imagined to have _ to minimize loss of water and conserve it.（分数：1.00）填空项 1:_(9).According to the authors imagination, in order to glide on the sand smoothl

33、y, the creature Lashlarm must have_.（分数：1.00）填空项 1:_(10).With its body almost totally under water, the Nirba can still breathe because its nostrils are on top of_（分数：1.00）填空项 1:_三、BPart Listenin(总题数：0，分数：0.00)四、BSection A/B(总题数：4，分数：105.00)（分数：21.00）(1). A. Teacher and student. B. Mother and son. C.

34、 Classmates. D. Brother and sister（分数：7.00）A.B.C.D.(2). A. Warm-hearted, self-disciplined, patient. B. Hot-tempered, diligent, kind. C. Easy-going, warm-hearted, stubborn. D. Self-centered, hard-working, considerate.（分数：7.00）A.B.C.D.(3). A. He spends much school time playing computer games. B. He of

35、ten dozes off in class. C. He doesnt take the assignments seriously. D. He plays computer games because the textbooks are dull and lectures are boring.（分数：7.00）A.B.C.D.（分数：28.00）(1).A. One of his cousins is getting married. B. The final exams are coming. C. He hasnt decided what to buy for his cousi

36、n.D. He has little time to tour California.（分数：7.00）A.B.C.D.(2). A. A week. B. Two weeks. C. Three weeks. D. Four weeks.（分数：7.00）A.B.C.D.(3). A. She cant sleep well these days. B. She is not good at some subjects. C. She is under the pressure of her parents love. D. She has suffered from headache.（分

37、数：7.00）A.B.C.D.(4). A. Pay attention to her diet. B. Study much harder. C. Go to the doctors. D. Talk to her parents.（分数：7.00）A.B.C.D.（分数：21.00）(1). A. It saw the end of its booming years worldwide. B. Its production and sales reached record levels. C. It became popular in some foreign countries. D.

38、 Its domestic market started to shrink rapidly.（分数：7.00）A.B.C.D.(2). A. They cost less. B. They tasted better. C. They were in fashion. D. They were widely advertised.（分数：7.00）A.B.C.D.(3). A. It is sure to fluctuate. B. It is bound to revive. C. It will remain basically stable. D. It will see no mor

39、e monopoly.（分数：7.00）A.B.C.D.（分数：35.00）(1). A. She is going to Finland. B. She has some visitors. C. She will visit Finland next week. D. She has just visited him this week.（分数：7.00）A.B.C.D.(2). A. To cancel his trip. B. To go to bed early. C. To catch a later flight. D. To ask for a wake up call.（分数

40、7.00）A.B.C.D.(3). A. Saturday afternoon was the mans busy hours. B. The man wont be able to enjoy a nap. C. Mr. Smith is an old friend of the man. D. The man wanted to take a long nap after lunch.（分数：7.00）A.B.C.D.(4). A. George wants to change his work. B. George is doing pretty good now. C. George

41、 doesnt like his work. D. George is not doing well with his work.（分数：7.00）A.B.C.D.(5). A. The woman is a dentist. B. The woman is a secretary. C. The woman is a receptionist. D. The woman is a patient.（分数：7.00）A.B.C.D.五、BSection B/B(总题数：3，分数：70.00)BPassage Two/B （分数：21.00）(1). A.To protect beachfron

42、t property. B.To reduce the traffic on beach roads. C.To provide privacy for homeowners. D.To define property limits.（分数：7.00）A.B.C.D.(2). A.By sending water directly back to the sea with great force. B.By reducing wave energy. C.By reducing beach width. D.By stabilizing beachfront construction.（分数：

43、7.00）A.B.C.D.(3). A.Protecting roads along the shore. B.Building on beaches with seawalls. C.Adding sand to beaches with seawalls. D.Stopping building seawalls.（分数：7.00）A.B.C.D.Passage One （分数：21.00）(1). A. New drugs. B. Settled debate. C. Skillful surgeons. D. Advanced equipment.（分数：7.00）A.B.C.D.(2

44、). A. The shortage of willing donors. B. The obtaining of moral approval. C. The complex technical procedure. D. The rejection from the immune system.（分数：7.00）A.B.C.D.(3). A. They are willing to donate their faces. B. They are concerned about moral problems. C. They would accept the idea of face tra

45、nsplant. D. They have no clue what face transplant means.（分数：7.00）A.B.C.D.Passage Two （分数：28.00）(1). A. Poor people become fewer. B. The poor are getting poorer. C. The poor are becoming rich. D. Rich people become fewer.（分数：7.00）A.B.C.D.(2). A. From other countries. B. From the urban areas. C. From

46、 the countryside. D. From the other races.（分数：7.00）A.B.C.D.(3). A. They want to try their luck in the city. B. They are fed up with their routine life. C. They have families and relatives to join. D. They can not make a living by farming.（分数：7.00）A.B.C.D.(4). A. The government has to cope with the p

47、roblem of population explosion. B. The government can not generate essential investment in public services. C. The government can not provide so many job opportunities for its people. D. The government will have to control the rapid increase of peoples income.（分数：7.00）A.B.C.D.六、BSection C/B(总题数：1，分数：77.00)Large companies need a way to reach the savings of the public at large. The same problem, on a smalleU U 1 /U /Ufaces practically every company trying to develop new products and create new jobs. There can be littleU U 2 /U /Uof raising the sort of sums needed from friends and people we