文档TPO51托福阅读passage3：The-Role-of-the-Ocean-in-Controlling-Climate原文文本-真题答案(DOC 11页).doc

1、TPO51托福阅读passage3:The Role of the Ocean in Controlling Climate原文文本+真题答案第三篇：社会学The Role of the Ocean in Controlling ClimateTo predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical proce

2、sses and interactions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe,thousands of calculations are performed at grid intersections to represent and assess ho

3、w conditions in the air, in the sea, and on land will change over time. Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models,

4、 and even more so, because there are aspects of climate that are not well understoodone of which is how the ocean impacts climate.The oceans role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and transport heat. In the sea, photosynthesis by marine

5、plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But what controls the oceans productivity? There are several limiting facto

6、rs, but results from a recent experiment suggest that in areas of the ocean where other nutrients are plentiful, iron may be one of the most important and, until recently, unrecognized variables controlling phytoplankton production. Some have proposed a radical, highly controversial and uncertain me

7、ans to counteract global warmingadding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects that could be detrimental to the ocean ecosyst

8、em.Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. W

9、hat is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, cryst

10、alline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides i

11、n the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is t

12、ransported by currents from the equator to the poles. Ocean circulation is strongly controlled by wind and by the seas balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation fr

13、om the ocean also supplies the precipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change thereflectivity Earths surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the at

14、mosphere come mainly from the sea and strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot,

15、dust, and other materials, are thought to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over

16、land, and in the sky that potentially influence warming. No wonder there is such uncertainty.题目Paragraph 1To predict what the climate will be like in the future, scientists must rely on sophisticated computer models. These models use mathematical equations to represent physical processes and interac

17、tions in the atmosphere, ocean, and on land. A starting point is usually based on current measurements or estimates of past conditions. Then, using a spherical grid laid out over the entire globe, thousands of calculations are performed at grid intersections to represent and assess how conditions in

18、 the air, in the sea, and on land will change over time.Because of their complexity and size, supercomputers are used to run full-scale climate models. Much of the uncertainty in their outputs comes from the way that various aspects of the climate are represented by different models, and even more s

19、o, because there are aspects of climate that are not well understoodone of which is how the ocean impacts climate.1.According to paragraph 1, the results of full-scale climate models are questionable in part becauseA.the supercomputers used for such modeling are large and complexB.thousands of calcu

20、lations have to be performed to assess conditionsC.past conditions cannot always be estimated accuratelyD.there are multiple ways to represent the same aspect of climate Paragraph 2The oceans role in global warming stems principally from its huge capacity to absorb carbon dioxide and to store and tr

21、ansport heat. In the sea, photosynthesis by marine plants and algae, especially phytoplankton, removes great quantities of carbon dioxide from the atmosphere. Hence, the greater the growth (productivity) of phytoplankton in the sea, the greater the removal of carbon dioxide. But whatcontrols the oce

22、ans productivity? There are several limiting factors, but results from a recent experiment suggest that in areas of the ocean where other nutrients are plentiful, iron may be one of the most important and, until recently, unrecognizedvariablescontrolling phytoplankton production.Some have proposed a

23、 radical, highly controversial and uncertain means to counteract global warmingadding iron to the oceans to induce phytoplankton blooms. Perhaps increased phytoplankton growth would use up a significant amount of carbon dioxide in the atmosphere, but perhaps not, and there might well be side effects

24、 that could be detrimental to the ocean ecosystem.2.The word “principally” in the passage is closet in meaning toA.obviouslyB.apparentlyC.mainlyD.originally3.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the

25、 meaning in important ways or leave out essential information.A.Iron may be one of the most important factors in controlling phytoplankton production in ocean waters that are rich in other nutrients.B.Results from a recent experiment suggest that several factors limiting phytoplankton production in

26、ocean waters have gone unrecognized.C.Although it was not recognized until recently, nutrients are plentiful in areas of the ocean where iron controls phytoplankton production.D.Until recently, the importance of iron was not taken into account in experiments concerning phytoplankton production.4.The

27、 word “controversial” in the passage is closest in meaning toA.experimentalB.fascinatingC.producing disagreementD.demonstrating poor judgment5.The word “induce” in the passage is closest in meaning toA.supply nutrients toB.cause the formation ofC.expandD.strengthen6.According to paragraph 2, how mig

28、ht increasing phytoplankton growth help lower global temperatures?A.By cooling the oceansB.By decreasing carbon dioxide levels in the oceanC.By reducing the amount of carbon dioxide in the atmosphereD.By transporting heat from the oceans surface to deeper levels Paragraph 3Within the ocean, the prod

29、uction of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atmosphere. What is not wellunderstood is

30、how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a solid, crystalline form of water, like ice

31、, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea landslides in the process. Consequently, h

32、ydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.7.According to paragraph 3, which of the following reduces atmospheric carbon dioxide?A.The weathering of limestoneB.The production of limestoneC.The recycling of carbo

33、n dioxideD.The presence of methane in gas hydrates8.According to paragraph 3, why are gas hydrates a possible threat to the global climate?A.If disturbed by offshore drilling, they can destroy limestone deposits.B.They can replace regular ice at certain locations.C.If melted, they may release a lot

34、of carbon dioxide into the atmosphere.D.They contain a lot of methane, which may be released as the ocean warms Paragraph 4The ocean is also a great reservoir and transporter of heat. Heat from the ocean warms the atmosphere and fuels tropical storms. Heat is transported by currents from the equator

35、 to the poles. Ocean circulation is strongly controlled by wind and by the seas balance of salt and heat. Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies the precipit

36、ation that creates fields of snow and ice at high latitudes. Snow and ice coverage change the reflectivity Earths surface and are an important influence on how much incoming radiation is either absorbed or reflected. Furthermore, clouds and water vapor in the atmosphere come mainly from the sea and

37、strongly influence climate. Surprisingly, clouds are one of the least understood and most poorly modeled parts of the climate change equation. Most climate modeling grids fail to take into account common-sized cloud formations. Aerosols, tiny particles of soot, dust, and other materials, are thought

38、 to seed cloud formation scatter incoming radiation and promote cooling, but this effect, which would counteract warming, is also only superficially understood. Computer models of climate change must take into account all of the processes within the ocean, over land, and in the sky that potentially

39、influence warming. No wonder there is such uncertainty.9.The word “fuels” in the passage is closest in meaning toA.provides energy forB.determines the route ofC.carriesD.breaks up10.Which of the following is NOT mentioned in paragraph 4 as a way in which the ocean affects the climate?A.It stores hea

40、tB.It moves heat from the equator toward the poles.C.It speeds up wind circulation.D.It warms up the atmosphere.11.Paragraph 4 suggests that a significant decrease in snow and ice fields at high latitudes would have what effect?A.More clouds and water vapor would be produced in the atmosphere.B.More

41、 of the Suns radiation would be absorbed by Earth.C.The oceans would cool more quickly.D.More precipitation would occur at low latitudes.12.Why does the author mention that “Most climate modeling grids fail to take into account common-sized cloud formations”?A.To suggest why the influence of clouds

42、on climate change is still undeterminedB.To explain why research on climate change does not focus on cloudsC.To help explain why it is unclear whether aerosols have the effect of counteracting warmingD.To explain in part why scientists are uncertain how much incoming radiation is absorbed or reflect

43、edParagraph 3Within the ocean, the production of limestone, in the form of calcium carbonate skeletons or shells, also reduces atmospheric carbon dioxide. However, when deposits of limestone become exposed and weathered on land or are recycled in the sea, carbon dioxide is released back into the atm

44、osphere. What is not well understood is how much carbon dioxide resides in the sea and at what rate it is taken up and recycled. Relatively new research has also discovered beneath the sea a new and potentially significant threat to skyrocketing Earth temperature: gas hydrates. Gas hydrates are a so

45、lid, crystalline form of water, like ice, except that they contain additional gas, typically methane, and are often found stored in ocean sediments. Increased ocean temperatures could cause gas hydrates to dissociate, releasing massive amounts of methane gas into the atmosphere and cause undersea la

46、ndslides in the process. Consequently, hydrates may, if released, significantly increase global warming as well as create a geologic hazard to offshore drilling operations.13.Look at the four squares that indicate where the following sentence could be added to the passageNor is carbon dioxide the on

47、ly gaseous substance in the ocean that may affect climate.Where would the sentence best fit?14.Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selected THREE answer choices that express the most important ideas in the passage. Some s

48、entences 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.The oceans affect the climate in numerous ways, some of which are poorly understood and therefore cannot be accurately modeled in computer climate programs.Answer ChoicesA.Estimates of future conditions are entered into supercomputers to calculate climate possibilities at various places on earth.B.Oceans absorb a great deal of carbon dioxide from the ai