1、托福-4 (1)及答案解析(总分：120.66，做题时间：90 分钟)一、BREADING/B(总题数：7，分数：35.50)READING SECTION DIRECTIONSThe Reading section measures your ability to read and understand passages in English. You will read five passages and answer questions about them. Answer all questions based on what is stated or implied in the p
2、assages. Most questions are worth one point. The last question in each set is worth more than one point. For this question, the directions will indicate how many points you can receive. Some passages have one or more words in bold type. For these bolded words, you will see a definition in a glossary
3、 at the end of the passage. Allow 20 minutes to read each passage and answer the questions about it. You may now begin the first passage. BSet 1/BNORTH AMERICAN GRASSLANDS1 In North America, native grasslands occur primarily in the Great Plains in the middle of the continent. The North American prai
4、rie biome is one of the most extensive grasslands in the world, extending from the edge of the Rocky Mountains in the west to the deciduous forest in the east, and from northern Mexico in the south to Canada in the north. Average annual rainfall ranges from about 40 cm (16 inches) in the west to 80
5、cm (31 inches) in the east. Average annual temperatures range between 10 degrees and 20 degrees Celsius (50 to 68 degrees Fahrenheit). In the moist regions of the North American grasslands, especially in the northern Great Plains, rainfall is distinctly seasonal, and temperatures can vary widely fro
6、m very hot in summer to bitter cold in winter. 2 One hundred years ago, the Great Plains grasslands were one vast, unbroken prairie. Much of the prairie is now farmland, the most productive agricultural region in the world, dominated by Bmonocultures/B of cereal grains. Wheat, barley, soybeans, corn
7、, and sunflowers occupy the land that was once prairie. In areas given over to grazing lands for cattle and sheep, virtually all the major native grasses have been replaced by Ualien/U species. 3 An important feature of the northern Great Plains grasslands is the presence of millions of glacial depr
8、essions that are now small ponds known as prairie potholes. They were formed during the most recent Ice Age, when streams flowed in tunnels beneath glacially formed sandy ridges. When the Ice Age ended around 12,000 years ago, the retreating glaciers created about 25 million depressions across a 300
9、,000-square-mile landscapeabout 83 potholes per square mile. As the ice blocks melted, much of the water was left behind, forming wetlands ranging in size from a tenth of an acre to several acres. The wetlands were soon surrounded by fluttering waves of grasses: shortgrass, mixed grass, and tallgras
10、s. 4 UToday these small wetlands still cover the prairies, although much of the landscape including both native grasses and potholeshas been transformed to cropland and grassland for grazing./U What does remain of the wetlands, however, still serves as an important breeding area for more than 300 bi
11、rd species, including large numbers of migrating shorebirds and waterfowl. The potholes fill up with water during spring rains and usually dry out by late summer. Every spring, birds arrive in great numbersnorthern pintails, mallards, coots, and pied-billed grebes4 to 6 million strong, to mate in th
12、e seasonal wetlands that dot portions of Minnesota, Iowa, North and South Dakota, Montana, Alberta, Saskatchewan, and Manitoba. Prairie pothole country produces half of North Americas 35 to 40 million ducks and is renowned worldwide as a “Uduck factory/U.“ 5 Recently biologists have discovered that
13、the prairie pothole region is potentially a vast carbon sink: a natural sponge that absorbs carbon dioxide emissions from cars, factories, and power plants. Carbon dioxide is the most common of all the pollutants acting as greenhouse gases that heat up the atmosphere. Fortunately, however, carbon di
14、oxide is captured naturally and stored in trees, soil, and plants. Scientists have termed Uthis/U “carbon sequestration.“ They have determined that prairie potholes hold an average of 2.5 tons of carbon per acre per year when not being farmed. This means that if the entire pothole region in the Unit
15、ed States and Canada were to stop being farmed, the region would store about 400 million tons of carbon over 10 yearsthe equivalent of taking almost 4 million cars off the road. Thus, preserving the potholes could be a way to Uoffset/U greenhouse gas emissions that are warming the planet. Glossary:
16、biome: one of the worlds major natural communities, classified by predominant vegetation monoculture: cultivation of large land areas with a single plant variety （分数：7.02）(1).All of the following statements are true of the northern Great Plains EXCEPT（分数：0.54）A.Summer temperatures are very hot, whil
17、e winter temperatures are very cold.B.An unbroken prairie now extends from the western mountains to the eastern forest.C.The original vegetation consisted of shortgrass, mixed grass, and tallgrass.D.A large number of small wetlands are found throughout the region.(2).What has taken place in the Grea
18、t Plains grasslands during the last century?（分数：0.54）A.The average annual rainfall has risen and fallen several times.B.Large parts of the prairie have been converted to agricultural use.C.Melting glaciers have formed numerous depressions in the soil.D.Scientists have transformed the region into one
19、 large carbon sink.(3).The word Ualien/U in paragraph 2 is closest in meaning to（分数：0.54）A.healthyB.simpleC.cheaperD.imported(4).The prairie potholes owe their origins mainly to（分数：0.54）A.the variation in temperature throughout the yearB.the glaciers that melted at the end of the last Ice AgeC.the h
20、eavy rains that fall in the spring and summerD.the increase in greenhouse gases in the atmosphere(5).Which sentence below best expresses the essential information in the highlighted sentence in paragraph 4? Incorrect choices change the meaning in important ways or leave out essential information.（分数
21、：0.54）A.The wetlands completely cover the landscape, making it difficult to grow crops and grass for grazing.B.The native grasses that grew in the potholes have been replaced with crops that are more beneficial.C.Except for the potholes region, the entire prairie has been converted to cropland and g
22、razing land.D.Even though a large portion of the prairies is used for crops and grazing, the small ponds remain.(6).The word Udot/U in paragraph 4 is closest in meaning to（分数：0.54）A.coverB.drainC.warmD.damage(7).Why does the author use the term “Uduck factory/U“ in paragraph 4?（分数：0.54）A.To point ou
23、t that ducks are the regions main product for exportB.To emphasize the areas value as a breeding ground for ducksC.To illustrate the tremendous growth of the poultry industryD.To show that the potholes are important to the regions economy(8).What is the function of a carbon sink?（分数：0.54）A.It regula
24、tes carbon emissions from human activities.B.It measures the amount of carbon dioxide in the ecosystem.C.It collects and drains seasonal rainwater from the soil.D.It removes carbon dioxide naturally from the atmosphere.(9).The word Uthis/U in paragraph 5 refers to（分数：0.54）A.the emission of carbon di
25、oxide from cars, factories, and power plantsB.the action of carbon dioxide as a greenhouse gasC.the capture and storage of carbon dioxide in trees, soil, and plantsD.the average amount of carbon dioxide in one acre of land(10).What can be inferred from paragraph 5 about carbon sequestration in the p
26、rairie pothole region?（分数：0.54）A.It depends on the land not being disturbed by agriculture.B.It creates a beneficial habitat for many species of birds.C.It is a leading cause of the warming of the atmosphere.D.It exceeds the amount of carbon captured anywhere else.(11).The word Uoffset/U in paragrap
27、h 5 is closest in meaning to（分数：0.54）A.preserveB.transformC.counteractD.measure(12).Look at the four squares, , and, which indicate where the following sentence could be added to the passage. Where would the sentence best fit? Today, however, the original grassland associations of plants and animals
28、 have been almost completely destroyed by human settlement. One hundred years ago, the Great Plains grasslands were one vast, unbroken prairie. Much of the prairie is now farmland, the most productive agricultural region in the world, dominated by monocultures of cereal grains. Wheat, barley, soybea
29、ns, corn, and sunflowers occupy the land that was once prairie. In areas given over to grazing lands for cattle and sheep, virtually all the major native grasses have been replaced by alien species. . Square . Square . Square . Square .（分数：0.54）A.B.C.D.(13).Read the first sentence of a summary of th
30、e passage. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
31、 The grasslands of North America consist mainly of the prairies in the Great Plains. _ _ _ Answer Choices（分数：0.54）填空项 1:_BSet 2/BPOLITICAL SYSTEMS OF THE TWENTIETH CENTURY1 Monarchy is a form of government in which authority is held by a single person, a monarch, whose right to rule is generally her
32、editary and lifelong. At the start of the twentieth century, monarchs ruled over most of the world, but by the middle of the century, only a handful remained. A series of revolutions in the preceding centuries had weakened the European monarchies, and while monarchs remained symbols of national unit
33、y, real power had passed to constitutional assemblies. Monarchy survived as a form in Europe only where the king or queen functioned as the symbolic head of a parliamentary state, as in Britain, the Low Countries, and Scandinavia. It lasted longer in the few small states of Asia and Africa that had
34、never come under direct colonial rule. By the 1960s, autocratic monarchy had become an outdated form of government. Throughout most of the world, people were considered citizens, not subjects, and the totality of the people were seen as constituting the state. 2 In most states where monarchical auth
35、ority was removed, some form of liberal democracy took its place. A liberal democracy is a state where political authority rests in the people acting through elected representatives and where an elected executive is responsible to the will of the people as a whole. UThe term/U applies to a broad gro
36、up of states with a parliamentary or representative political tradition. Liberal democracies differ from the communist states known as Upeoples democracies/U, in which the Communist party holds the ultimate authority. Generally, liberal democracies follow the parliamentary Upattern/U, with the execu
37、tive power vested in a cabinet responsible to the parliament and drawn from the majority party or combination of parties. In the United States, an independently elected executive, the president, functions separately from the legislative authority, the congress. 3 The doctrine that all of the people
38、had effective authority, or sovereignty, became the basis for the functioning of democratic states. This doctrine of popular sovereignty became all-inclusive as citizenship rights were extended to classes formerly excluded and to women. The liberal democratic state claimed the right to control every
39、 aspect of human life according to the will of the people, except where limits on state control were directly stated in a bill of rights in a democratic constitution and recognized in practice. 4 All democratic states, both parliamentary and presidential, changed in form during the twentieth century
40、. To meet the needs of an urban industrial society, states generally enlarged their scope of activity to control economic power and to provide common services to the people. The expansion of state activity and extension of state services involved a new view of legislation and its role in society. Th
41、e passing of laws came to be seen as a way to promote the well being of the people. With this new concept of legislation, the number of new laws increased immensely, particularly in the areas of social welfare, education, health and safety, and economic development. 5 The trend toward liberal democr
42、acy continued throughout the century, but at various times there was also a tendency toward a revival of authoritarian rule. In a number of states, democratic governments could not cope with the crises of the time. UIn these cases, some form of totalitarian dictatorship emerged, replacing popular so
43、vereignty with the total power of the state. /UIn some instances, monarchy gave way directly to dictatorship. In others, dictatorial regimes took over democratically organized states, notably in Eastern Europe in the years between the two world wars, in new states of Asia and Africa in the 1950s, an
44、d sporadically in Central and South America. 6 Authoritarian governments showed three principle characteristics. First, there was a head of state or leader with exceptional powers, with a party to support him. Second, the legislative body was elected by a system that prohibited parties opposed to th
45、e regime, and third, there was a bureaucratic administration that was in no way subject to popular control. The most extreme position on these points was taken by Hitlers totalitarian National Socialist State in the 1930s. Glossary: autocratic: characterized by unlimited power autocratic: characteri
46、zed by complete obedience to authority, lacking individual freedom （分数：6.05）(1).What point does the author make about monarchs in the twentieth century?（分数：0.55）A.Monarchs did not allow the people to vote in democratic elections.B.Monarchs did not have real power but were symbols of national unity.C
47、.The monarch in most countries was a king rather than a queen.D.Monarchs were responsible for starting many popular revolutions.(2).The word Usurvived/U in paragraph 1 is closest in meaning to（分数：0.55）A.remainedB.developedC.changedD.returned(3).The phrase UThe term/U in paragraph 2 refers to（分数：0.55
48、）A.monarchical authorityB.liberal democracyC.will of the peopleD.communist(4).Why does the author mention Upeoples democracies/U in paragraph 2?（分数：0.55）A.To contrast two concepts of where political authority restsB.To suggest that peoples democracies originated in liberal democraciesC.To explain differences between oneparty and two-party systemsD.To describe the parliamentary system of peoples democracies(5).The word Upattern/U in paragraph 2 is closest in meaning to（分数：0.55）A.choiceB.partyC.
