1、大学英语四级 183 及答案解析(总分：746.58，做题时间：130 分钟)一、Writing (30 minutes)(总题数：1，分数：30.00)1.For this part, you are allowed thirty minutes to write a welcome speech on behalf of the department to welcome Professor Thomas to give a lecture. You should write at least 120 words according to the guidelines given belo
2、w in Chinese. 假设你所在的化学系邀请著名化学教授(Thomas)做讲座，请你写一篇欢迎词。内容主要包括： 1表示热情欢迎 2简要介绍教授的情况 （分数：30.00）_二、Reading Comprehensio(总题数：1，分数：71.00)Rainforests Did you know there are two types of Rainforestthe temperate and the tropical? Tropical rainforests are found close to the equator. Temperate rainforests are fou
3、nd along coasts in the temperate zone, such as the Pacific Northwest of the USA. Both are endangered! Rainforests Endangered! Today only about three percent of the original temperate rainforest in the U. S. A. remains, mostly inside Olympic National Park in Washington State. Prior to the arrival of
4、homesteaders just over a century ago, the Olympic Peninsula contained more than a million acres of old-growth spruce and hemlock. Because of habitat destruction, many plants and animals have become “island dwellers“ inside the park now. Tropical rainforests comprise only 40% of the worlds tropical f
5、orests and only 20% of the worlds total forests. They cover 6%7% of the Earths land surface. Half of the worlds plant and animal species live in the tropical rainforests of the world. Thirty acres of trees are cut in the tropical rainforests every minute. As you read this, tropical rainforests are s
6、hrinking. Each second a portion of rainforest the size of a football field is destroyed or damaged. What Makes the Tropical Rainforest Special? -The rainforests are home to half of the Earths plant and animal species. -They are winter homes to many birds that breed in temperate latitudes. -Tropical
7、rainforests are some of the most beautiful wildernesses on our planet. -They are home to tribal cultures that have survived successfully in the forests for many thousands of years. -The forests are a potential source of medicinal plants that may benefit everyone on Earth. -The ecosystem of the rainf
8、orest is based on the most complex interdependence of plants and animals. This is both the forests strength and its weakness: highly specialized organisms are particularly vulnerable to disturbance, because they cannot adapt fast enough to survive the change. -Tropical rainforests help maintain glob
9、al rain and weather patterns. Much of the water that evaporates from the trees returns in the form of rainfall. Removal of the forest can change the natural rainfall patterns. Tropical Rainforest Layers Tropical rainforests have four layers: Emergent Layer These giant trees thrust above the dense ca
10、nopy layer(树冠层) and have huge mushroom-shaped crowns. These trees enjoy the greatest amount of sunlight but also must endure high temperatures, low humidity, and strong winds. Canopy Layer The broad, irregular crowns of these trees form a tight, continuous canopy 60 to 90 feet above the ground. The
11、branches are often densely covered with other plants (epiphytes) and tied together with vines (lianas). The canopy is home to 90% of the organisms found in the rain forest; many seeking the brighter light in the treetops. Understory Receiving only 2%15% of the sunlight that falls on the canopy, the
12、understory is a dark place. It is relatively open and contains young trees and leafy herbaceous plants that tolerate low light. Many popular house plants come from this layer. Only along rivers and roadways and in treefall and cut areas is sunlight sufficient to allow growth to become thick and impe
13、netrable Forest Floor The forest floor receives less than 2% of the sunlight and consequently, little grows here except plants adapted to very low light. On the floor is a thin layer of fallen leaves, seeds, fruits, and branches that very quickly decomposes. Only a thin layer of decaying organic mat
14、ter is found, unlike in temperate deciduous (落叶性的) forests. Soil and Nutrient Recycling Most tropical rainforest soils are relatively poor in nutrients. Millions of years of weathering and torrential rains have washed most of the nutrients out of the soil. More recent volcanic soils, however, can be
15、 very fertile. Tropical rain forest soils contain less organic matter than temperate forests and most of the available nutrients are found in the living plant and animal material. Nutrients in the soil are often in forms that are not accessible by plants. Constant warmth and moisture promote rapid d
16、ecay of organic matter. When a tree dies in the rainforest, living organisms quickly absorb the nutrients before they have a chance to be washed away. When tropical forests are cut and burned, heavy rains can quickly wash the released nutrients away, leaving the soil even more impoverished. Causes o
17、f Destruction Tropical rainforests are being cut at an alarming rate. Although estimates vary, some scientists believe that we are losing an area of rainforest the size of Pennsylvania each year. If deforestation continues at this rate we may lose rainforests altogether within the next one hundred y
18、ears. Tropical deforestation occurs for a number of reasons. As human populations increase in tropical regions, people move away from the overcrowded cities into the forest areas where they practice small-scale farming. Commercial agricultural projects may require conversion of large plots of rainfo
19、rest land and may cause more permanent damage. Logging of forests for firewood, charcoal, building materials, and other wood products is another cause of deforestation. The conversion of rainforest to pasture land for cattle ranching has led to the destruction of millions of acres of forest. Mining
20、for gold, bauxite from which aluminum is made, and other minerals can lead to the drastic destruction of the land. Once the land is scarred by mining efforts it is left vulnerable to massive erosion. Other events and issues such as natural disasters, war, the construction of dams, and poverty in dev
21、eloping countries also contribute to the destruction of tropical rainforests. What Can You Do to Help Save the Tropical Rainforest? Preserving tropical rainforests involves more than just deciding not to cut trees. Social, political and economic factors all need to be taken into consideration. The f
22、ollowing are some suggestions about how you can contribute to the solution. -Learn more about tropical rainforests and the plants and animals, including people, which live there. Investigate the complex issues surrounding deforestation and possible solutions through further reading. -Write letters t
23、o your congressional representatives or your local paper to express concern about the destruction of the tropical rainforests. The more you know about the topic and issues, the more specific you can be in suggesting actions you would like your elected officials to take. -Visit tropical countries to
24、see the rainforest. Gaining firsthand experience is one of the best ways to develop an understanding of and commitment to an issue. -Work to protect tropical rainforests and their indigenous peoples. -Think globally and act locally. Practices at home, like the ones listed below, can have an impact o
25、n the preservation of rainforests. -Recycling aluminum cans reduces the need for bauxite, which must be mined from the ground in tropical countries. Bauxite is the source of aluminum. -Buy only pets which were captive bred here in the United States. Those which were not bred here may have been taken
26、 from the wild and imported illegally from tropical countries. When purchasing tropical woods for furniture or construction, investigate the source of the wood to determine whether it was grown in a sustainable manner. In all things you do, practice the environmentally sound use and reuse of our res
27、ources. This will not only have a positive impact on the tropical rainforest but on all the ecosystems of the world. （分数：71.00）(1).The passage gives a general description of the tropical rainforests.（分数：7.10）A.YB.NC.NG(2).Tropical rainforests comprise only 40% of the worlds tropical forests and only
28、 20% of the worlds total forests.（分数：7.10）A.YB.NC.NG(3).The ecosystem of the rainforest is based on the most complex interdependence of plants and animals.（分数：7.10）A.YB.NC.NG(4).The rainforests are home to one-third of the Earths plant and animal species.（分数：7.10）A.YB.NC.NG(5).The giant trees above
29、the dense canopy layer(树冠层) cannot enjoy sunlight.（分数：7.10）A.YB.NC.NG(6).When people cut and burn tropical forests, heavy rains can wash the released nutrients away, leaving the soil even more fertile.（分数：7.10）A.YB.NC.NG(7).Tropical rain forest soils contain less volcanic soils than temperate forest
30、s.（分数：7.10）A.YB.NC.NG(8).Commercial agricultural projects may require conversion of large plots of rainforest land and may cause_.（分数：7.10）_(9).When purchasing tropical woods for furniture or construction, investigate the source of the wood to determine whether it was grown in_.（分数：7.10）_(10).To pre
31、serve tropical rainforests, social, political and economic factors all need to be_.（分数：7.10）_三、Listening Comprehens(总题数：1，分数：15.00)A.Whether it is necessary for her to write to Mr. Smith.B.Who is going to contact Mr. Smith.C.What they are going to do at the meeting.D.Where they are going to meet Mr.
32、 Smith.A.The tape was missing.B.Paul brought the tape to the party.C.The tape had been returned to Jack.D.Paul lent his tape to Jack.A.At 1:00.B.At 2:00.C.Around 3:00.D.Around 5:00.A.The man is about to board the plane to Los Angeles.B.The man is going to take the next direct flight to San Francisco
33、.C.The man wants to take a non-stop flight to San Francisco.D.The man wants to go to Los Angeles.A.The woman has trouble getting along with the professor.B.The woman regrets having taken up much of the professors time.C.The woman knows the professor has been busy.D.The woman knows the professor has
34、run into trouble.A.Because she doesnt want to.B.Because she has to work in a restaurant.C.Because she has to go to another party.D.Because she has dated with her boyfriend.A.She is trying to find a good chair.B.She doesnt know where the chair is now.C.She thinks the chair is actually comfortable.D.S
35、hes never sat in that chair before.A.The rose gardens are on the opposite side of the park.B.The roses in the gardens are not the best.C.The rose gardens are on the west side of the park.D.The roses grow outside the park, not inside it.四、Section B(总题数：2，分数：10.00)A.To see his old friend Ann Smith.B.T
36、o buy a two-bedroom apartment.C.To talk to the rental agent there.D.To rent a two-bedroom apartment.A.410 dollars a monthB.430 dollars a monthC.450 dollars a monthD.500 dollars a monthA.He is probably a teacher.B.He is probably a bus driver.C.He is probably a swimming trainer.D.He is probably a mana
37、ger.A.To talk to the rental agent.B.To find the best location.C.To pay some damage deposit.D.To sign a lease.A.At a pharmacy.B.At a clinic.C.On a campus road.D.At a grocery.A.To travel to Alaska with his brother.B.To give a talk about his trip to Alaska.C.To drive to Los Angeles for a wedding.D.To i
38、nvite Sue to meet his brother.A.For not being able to go to Alaska.B.For her not going to a wedding party.C.For driving six hours to Los Angeles.D.For not being able to go to the mans family.A.People in most countries of the world today are not opposed to living in flats.B.English people, like most
39、people in other countries, dislike living in flats.C.People in Britain are forced to move into high blocks flats.D.Modern flats still fail to provide the necessary facilities for living.A.They were sold to people before necessary facilities were installed.B.They were usually not large enough to acco
40、mmodate big families.C.They were mostly inhabited by people who did not earn much.D.They provided playgrounds for children on the top of the buildings.A.Because the living expenses for each individual family are higher.B.Because they believe people like to live in houses with gardens.C.Because it in
41、volves higher cost compared with the building of houses.D.Because the disposal of rubbish remains a problem for those living in flats.A.Beauty.B.Loyalty.C.Luck.D.Durability.A.He wanted to follow the tradition of his country.B.He believed that it symbolized an everlasting marriage.C.It was thought th
42、at a blood vessel in that finger led directly to the heart.D.It was supposed that the diamond on that finger would bring good luck.A.The two people can learn about each others likes and dislikes.B.The two people can have time to decide if they are a good match.C.The two people can have time to shop
43、for their new home.D.The two people can earn enough money for their wedding.A.The number of students they take in is limited.B.They receive little or no support from public taxes.C.They are only open to children from rich families.D.They have to pay more taxes.A.Private schools admit more students.B
44、.Private schools charge less than religious schools.C.Private schools run a variety of programs.D.Private schools allow students to enjoy more freedom.A.The churches.B.The program designers.C.The local authorities.D.The state government.六、Section C(总题数：1，分数：10.00)We often hear the (36) 1, “ Everybod
45、y talks about weather, but nobody does anything a-bout it.“ This is really not (37) 2today. Something is, indeed, being (38 ) 3. Today, meteorology is used to make peoples lives (39) 4and better. Meteorologists are constantly studying the weather. Some meteorologists (40) 5the weather, others analyz
46、e weather information, and still others make (41) 6about the weather (42) 7. The United States National Weather Service (43) 8a network of weather stations through the U. S. The Weather Service has more than 400 stations where information about weather is collected and recorded. (44) 9. The Weather
47、Service issued 24-hour weather . It also issues 5-day , 10-day and even 30-day . (45) 10 . In the year 1959, the United States launched its first weather satellite. This satellite was specially designed to collect, record, and send back weather information to earth. (46) 11. They continue to provide valuable weather information to meteorologist in all parts of the world. （分数：10.00）填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_七、Reading Comprehensio(总题数：2，分数：355.00)Teaching children to read well from the start is the most impor
