1、-0308托福试题阅读（55minutes）Question 1-11If food is allowed to stand for some time, it putrefies .When the putrefied materialis examined microscopically ,it is found to be teeming with bacteria. Where do these bacteria come from , since they are not seen in fresh food? Even until the mid-nineteenth centur
2、y, many people believed that such microorganisms originated by spontaneous(5 ) generation ,a hypothetical process by which living organisms develop from nonlivingmatter.The most powerful opponent of the theory of spontaneous generation was the French chemist and microbiologist Louis Pasteur(1822-189
3、5).Pasteur showed that structures present in air closely resemble the microorganisms seen in putrefying materials .He did (10) this by passing air through guncotton filters, the fibers of which stop solid particles. Afterthe guncotton was dissolved in a mixture of alcohol and ether, the particles th
4、at it had trapped fell to the bottom of the liquid and were examined on a microscope slide .Pasteurfound that in ordinary air these exists a variety of solid structures ranging in size from 0.01 mm to more than 1.0 mm .Many of these bodies resembled the reproductive (15)structures of common molds, s
5、ingle-celled animals, and various other microbial cells .As many as 20 to 30 of them were found in fifteen liters of ordinary air ,and they couldnot be distinguished from the organisms found in much larger numbers in putrefying materials .Pasteur concluded that the organisms found in putrefying mate
6、rials originated from the organized bodies present in the air .He postulated that these bodies are constantly(20)being deposited on all objects.Pasteur showed that if a nutrient solution was sealed in a glass flask and heated to boiling to destroy all the living organisms contaminating it, it never
7、putrefied .The proponents of spontaneous generation declared that fresh air was necessary for spontaneous generation and that the air inside the sealed flask was affected in some way (25)by heating so that it would no longer support spontaneous generation. Pasteur constructed a swan-necked flask in
8、which putrefying materials could he heated to boiling, but aircould reenter. The bends in the neck prevented microorganisms from getting in the flask. Material sterilized in such a flask did not putrefy.1,What does the passage mainly discuss?(a)Pasteurs influence on the development of the microscope
9、.(b)The origin of the theory of spontaneous generation .(c)The effects of pasteurization on food.(d)Pasteurs argument against the theory of spontaneous generation .2,The phrase “teeming with ”in line 2 is closest in meaning to(a)full of(b)developing into(c)resistant to(d)hurt by 3,Which of the follo
10、wing questions did the theory of spontaneous generation attempt to answer?(a)What is the origin of the living organisms are seen on some food?(b)How many types of organisms can be found on food?(c)What is the most effective way to prepare living organisms for microscopic examination?(d)How long can
11、food stand before it putrefies?4,The word “resemble” in line 9 is closest in meaning to(a)benefit from(b)appear similar to(c)join together with(d)grow from5,The purpose of the “guncotton” mentioned in paragraph 2 was to(a)trap particles for analysis(b)slow the process of putrefaction(c)increase the
12、airflow to the microscopic slide(d)aid the mixing of alcohol and ether6,The author mention “1.0mm”in line 14 in describing the (a)thickness of a layer of organisms that was deposited on an object(b)diameter of the fibers that were in the guncotton filters(c)thickness of the microscope slides that we
13、re used(d)size of the particles that that were collected7.The word “postulated”in line 19 is closest in meaning to(a)analyzed(b)doubted(c)persuaded(d)suggested8.The objects that Pasteut removed from the air in his experiment were remarkable because they were(a)primarily single-celled organisms(b)no
14、different from objects found in putrefying materials(c)fairly rare(d)able to live in a mixture of alcohol and ether9.The word “it” in line 22 refers to (a)a nutrient solution(b)a glass flask(c)boiling(d)spontaneous generation10.According to paragraph 3,proponents of spontaneous generation believed t
15、hat which of the following was important for the process to succeed ?(a)A sealed container(b)Fresh air(c)Heat(d)The presence of nutrients11.It can be inferred from paragraph 3 that Pasteur employed a swam-necked flask to(a)store sterilized liquids for use in future experiments(b)prevent heat from bu
16、ilding up in a solution (c)disprove a criticism of his conclusions(d)estimate the number of organisms in a liter of airQuestions 12-20In the early decades of the United States ,the agrarian movement promoted the farmeras societys hero. In the minds of agrarian thinkers and writers ,the farmer was a
17、person on whose well-being the health of the new country depended .The period between the Revolution, which ended in 1783,and the Civil War ,which ended in 1865 ,was the age of (5 )the farmer in the United States .Agrarian philosophers ,represented most eloquently byThomas Jefferson, celebrated farm
18、ers extravagantly for their supposed centrality in a good society, their political virtue ,and their Superior morality .And virtually all policy makers, whether they subscribed to the tenets of the philosophy held by Jefferson or not, recognized agriculture as the key component of the American econo
19、my .Consequently ,government at (10) all levels worked to encourage farmers as a social group and agriculture as economic enterprise.Both the national and state governments developed transportation infrastructure,building canals, roads, bridges, and railroads ,deepening harbors ,and removing obstruc
20、tions from navigable streams .The national government imported plant and animal varieties and(15) launched exploring expeditions into prospective farmlands in the West .In addition ,government trade policies facilitated the exporting of agricultural products.For their part ,farmers seemed to meet th
21、e social expectations agrarian philosophershad for them ,as their broader horizons and greater self-respect, both products of the Revolution ,were reflected to some degree in their behavior .Farmers seemed to become (20) more scientific ,joining agricultural societies and reading the farm newspapers
22、 that sprang up throughout the country .They began using improved implements, tried new crops and pure animal breeds , and became more receptive to modern theories of soil improvement .They also responded to inducements by national and state governments .Farmers streamed to the West ,filling frontie
23、r lands with stunning rapidity .But farmers responded (25) less to the expectations of agrarians and government inducements than to growing market opportunities .European demand for food from the United States seemed insatiable . War, industrialization , and urbanization all kept demand high in Euro
24、pe . United States cities and industries grew as well; even industries not directly related to farming thrived because of the market, money ,and labor that agriculture provided . 12.What does the passage mainly discuss?(a)The agrarian philosophy of Thomas Jefferson(b)The role of the national governm
25、ent in the development of agriculture(c)Improvements in farming techniques(d)The impact of the increased importance of the farmer13.The word “depended” in line 3 is closest in meaning to(a)improved(b)relied(c)demanded(d)explained14.The author mentions Thomas Jefferson in paragraph 1 as an example of
26、(a)a leader during the Revolution(b)an inventor of new farming techniques(c)a philosopher who believed farmers were essential to the creation of a good society(d)a farmer who guided the agrarian movement toward an emphasis on economic development15.The phrase “subscribed to” in line 8 is closest in
27、meaning to(a)contributed to(b)agreed with(c)thought about(d)expanded on16.Which of the following statements is supported by the information in paragraph 1?(a)All government policy makers accepted Jeffersons views of agriculture and farmers.(b)Agricultural production declined between 1783 and 1861.(c
28、)The majority of farmers worked for the government.(d)Agriculture was a vital part of the nations economy.17.According to the passage , the national and state governments did all of the following EXCEPT(a)build roads(b)import new plant varieties(c)give farmers money for their crops(d)develop policie
29、s that helped farmers export their products18.All of the following are mentioned as examples of farmers meeting the expectations of agrarian philosophers EXCEPT(a)obtaining information from farm newspapers(b)accumulating personal wealth(c)planting new crops (d)becoming more scientific19.The word “st
30、unning” in line 24 is closest in meaning to(a)predictable(b)impressive(c)famous(d)gradual20.Which of the following statements is best supported by paragraph 4?(a)Agricultural development contributed to development in other parts of the economy.(b)European agricultural products were of a higher quali
31、ty than those produced in the United States.(c)The growing settlement of the West led to a decrease in agricultural production.(d)Farmers were influenced more by government policies than by market opportunities.Question 21-29 The wide variety of climates in North America has helped spawn a complex p
32、attern of soil regions. In general, the realms soils also reflect the broad environmental partitioning into “humid America” and “arid America.” Where annual precipitation exceeds 20 inches(50 centimeters),soils in humid areas tend to be acidic in chemical content, Since crops (5 ) do best in soils t
33、hat are neither acidic(higher in acid content) nor alkaline(higher in salt content).fertilization is necessary to achieve the desired level of neutrality between the two. Arid Americas soils are typically alkaline and must be fertilized back toward neutrality by adding acidic compounds. Although man
34、y of these dryland soils, particularly in the Great Plains, are quite fertile, European settlers learned over a century ago that (10) water is the main missing ingredient in achieving their agricultural potential. In the 1970s, certain irrigation methods were perfected and finally provided a real op
35、portunity to expand more intensive farming west from the Central Lowland into the drier portions of the Great Plains. Glaciation also enhanced the rich legacy of fertile soils in the central United States,both from the deposition of mineral-rich glacial debris left by meltwater(15) and from thick la
36、yers of fine wind-blown glacial material, called loess, in and around the middle Mississippi Valley. Natural vegetation patterns could be displayed on a map of North America, but the enormous human modification of the North American environment in modern times has all but reduced this regionalizatio
37、n scheme to the level of the hypothetical. Nonetheless,(20) the humid America-arid America dichotomy is still a valid generalization: the natural vegetation of areas receiving more than 20 inches of water yearly is forest, whereas the drier climates give rise to a grassland cover. The forests of Nor
38、th America tent to make a broad transition by latitude. In the Canadian North, needle-leaf forests dominate, but these coniferous trees become mixed with broadleaf deciduous trees as one crosses the (25) border into the Northeast United States. As one proceeds toward the Southeast, broadleaf vegetat
39、ion becomes dominant. Arid America mostly consists of short-grass prairies or stepper. The only areas of true desert are in the Southwest.21 What aspect of North America does the passage mainly discuss?(A)The wide variety of climates(B)Soil types and vegetation patterns(C)Improved irrigation methods
40、 and the expansion of agriculture(D)The change in precipitation patterns22 The word “spawn ” in line 1 is closest in meaning to (A)distinguish(B)eliminate(C)protect (D)create23 The word “partitioning” in line 2 is closest in meaning to (A)division(B)modification(C)opening(D)circulating24 According t
41、o the passage, acidic soils tent to be associated with(A)a high salt content(B)an increase in farming(C)large amounts of rain(D)glacial meltwater25 The word “enhanced” in line 13 is closest in meaning to (A)implied(B)increased(C)indicated(D)informed26 How did glacial meltdown affect the soil in Nort
42、h America?(A)It redistributed the soil types(B)It added salt to the soil(C)It made the soil more neutral in content(D)It added minerals to the soil27 The phrase “this regionalization scheme” in line 19 refers to the (A)movements of glacial deposits(B)patterns of natural vegetation(C)human modificati
43、on of the North American environment(D)distinction between humid America and arid America28 The word “transition” in line 23 is closest in meaning to (A)elevation(B)change(C)advantage(D)condition29 The passage supports which of the following statements?(A)Arid America is not necessarily characterize
44、d by the presence of deserts(B)Most of Canada and the northeastern United States consists of short-grass prairies wherever natural vegetation has not been modified by humans(C)The accumulation of loess is primarily the result of irrigation(D)Glaciation removed the fertile layer of soil from much of
45、the Mississippi ValleyQuestions 30-40 Most sources of illumination generate light over an appreciable period, and indeed if an object is lit for a very brief time(less that 1/25 second), the human eye will not react in time to see the object. A photographic emulsion-that is, a light-sensitive coatin
46、g on photographic film, paper, or glass-will, however, record much shorter bursts of light. A (5 ) photographic flash can therefore be used to capture high-speed movement on film as well as to correct deficiencies of the normal surrounding lighting. Photoflash is now generated electronically, but th
47、e earliest form, first used in 1864, was a paper bag containing magnesium wire and some oxygen-rich substance, such as potassium chlorate. When the bag was ignited, the metal burned with an intense flash. A contemporary observer reported(10) that “this quite unsafe device seems to have done nothing worse that engulf the room in dense smoke and lead to pictures of dubious quality and odd poses.” The evolution of the photoflash was slow, flashbulbs, containing fine wire made of a metal, such as magnesium or aluminum
