Before 1965 many scientists pictured the circulation of the ocean’s water mass as consisting of large, slow-moving currents, such as the Gulf Stream. That view, based on 100 years of observations made around the globe, produced only a rough approximation of the true circulation. But in the 1950’s and the 1960’s, researchers began to employ newly developed techniques and equipment, including subsurface floats that move with ocean currents and emit identification signals, and ocean-current meters that record data for months at fixed locations in the ocean. These instruments disclosed an unexpected level of variability in the deep ocean. Rather than being characterized by smooth, large-scale currents that change seasonally (if at all), the seas are dominated by what oceanographers call mesoscale fields; fluctuating, energetic flows whose velocity can reach ten times the mean velocity of the major currents.
Mesoscale phenomena—the oceanic analogue of weather systems-often extend to distances of 100 kilometers and persist for 100 days (weather systems generally extend about 1,000 kilometers and last 3 to 5 days in any given area). More than 90 percent of the kinetic energy of the entire ocean may be accounted for mesoscale variability rather than by large-scale currents. Mesoscale phenomena may, in fact, play a significant role in oceanic mixing, air-sea interactions, and occasional but far-reaching climatic events such as EI Nino, the atmospheric-oceanic disturbance in the equatorial Pacific that affects global weather patterns.
Unfortunately, it is not feasible to use conventional techniques to measure mesoscale fields. To measure them properly, monitoring equipment would have to be laid out on a grid at intervals of at most 50 kilometers, with sensors at each grid point lowered deep in the ocean and kept there for many months. Because using these techniques would be prohibitively expensive and time-consuming, it was proposed in 1979 that tomography be adopted to measure the physical properties of the ocean. In medical tomography X-rays map the human body’s density variations (and hence internal organs); the information from the X-rays, transmitted through the body along many different paths, is recombined to form three-dimensional images of the body’s interior. It is primarily this multiplicative increase in data obtained from the multipath transmission of signals that accounts for oceanographer’s attraction to tomography; it allows the measurement of vast areas with relatively few instruments. Researchers reasoned that low-frequency sound waves, because they are so well described mathematically and because even small perturbations in emitted sound waves can be detected, could be transmitted through the ocean over many, different paths and that the properties of the ocean’s interior—its temperature, salinity, density, and speed of currents—could be deduced on the basis of how the ocean altered the signals. Their initial trials were highly successful, and ocean acoustic tomography was born.
26. According to the passage, scientist are able to use ocean acoustic tomography to deduce the properties of the ocean’s interior in part because ______.
27. Which of the following is most similar to medical tomography as it is described in the passage?
28. The author mentions EI Nino primarily in order to emphasize which of the following points?
29. Which of the following best describes the organization of the third paragraph of the passage?
30. The passage suggests that which of the following would be true if the ocean’s circulation consisted primarily of large, slow-moving currents?
问题1选项
A.low-frequency sound waves are well described mathematically
B.mesoscale phenomena are so large as to be easily detectable
C.information from sound waves can be recombined more easily than information from X-rays
D.density variations in the ocean are mathematically predictable
问题2选项
A.The use of ocean-current meters to determine the direction and velocity of the ocean’s mesoscale fields.
B.The use of earthquake shock-wave data collected at several different locations and combined to create a three-dimensional image of the Earth’s interior.
C.The use of a grid-point sensory system to map global weather patterns.
D.The use of subsurface floats to map large-scale circulation in the ocean.
问题3选项
A.The brief duration of weather patterns.
B.The difficulty of measuring the ocean’s large-scale currents.
C.The effectiveness of low-frequency sound waves in mapping the ocean.
D.The possible impact of mesoscale fields on weather conditions.
问题4选项
A.Opposing views are presented, elaborated, and then reconciled.
B.A problem is described, and then a solution is discussed and its effectiveness is affirmed.
C.An argument is advanced, then refuted, and an alternative is suggested.
D.A hypothesis is presented, qualified, and then reaffirmed.
问题5选项
A.Conventional measuring techniques would be a feasible method of studying the physical properties of the ocean.
B.The influence of mesoscale fields on global weather patterns would remain the same.
C.The majority of the ocean’s kinetic energy would be derived from mesoscale fields.
D.Atmospheric-oceanic disturbances such as EI Nino would occur more often.
第1题:A
第2题:B
第3题:D
第4题:B
第5题:A
26.【选项释义】
26. According to the passage, scientist are able to use ocean acoustic tomography to deduce the properties of the ocean’s interior in part because ______. 26. 根据这篇文章，科学家能够使用海洋声学层析成像来推断海洋内部的特性，部分原因是______。
A. low-frequency sound waves are well described mathematically A. 低频声波在数学上描述得很好
B. mesoscale phenomena are so large as to be easily detectable B. 中尺度现象很大，很容易探测到
C. information from sound waves can be recombined more easily than information from X-rays C. 声波的信息比X射线的信息更容易重组
D. density variations in the ocean are mathematically predictable D. 海洋的密度变化在数学上是可以预测的
【考查点】事实细节题。
【解题思路】根据题干定位到文章倒数第二句“研究人员推断，因为它们（low-frequency sound waves）在数学上得到了很好的描述（so well described mathematically），而且即使是发出的声波中的微小扰动也能被探测到，所以低频声波可以通过许多不同的路径在海洋中传播，海洋内部的特性（the properties of the ocean’s interior），如温度、盐度、密度和流速等，可以根据海洋如何改变信号来推断”可知，科学家能够使用海洋声学层析成像来推断海洋内部的特性的原因是低频声波在数学上得到了很好的描述，且能探测到发出的声波中的微小扰动，所以A项正确。
【干扰项排除】
B选项定位第三段第一句“不幸的是，使用传统技术测量中尺度场是不可行的”可知，easily detectable并不符合原文，而且与题干无关，该项属于出处错位；
C选项没有提到声波信息和X射线信息的比较，属于无中生有；
D选项在文中提到的是“海洋内部的特性，如温度、盐度、密度和流速等，可以根据海洋如何改变信号来推断”，所以海洋的密度是根据海洋改变的信号来预测的，该项曲解原文。
27.【选项释义】
27. Which of the following is most similar to medical tomography as it is described in the passage? 27. 下面哪项与文章中描述的医学断层扫描最相似？
A. The use of ocean-current meters to determine the direction and velocity of the ocean’s mesoscale fields. A. 利用洋流计来确定海洋中尺度场的方向和速度。
B. The use of earthquake shock-wave data collected at several different locations and combined to create a three-dimensional image of the Earth’s interior. B. 利用在几个不同地点收集的地震冲击波数据，并结合起来创建一个地球内部的三维图像。
C. The use of a grid-point sensory system to map global weather patterns. C. 使用网格点感知系统来绘制全球天气模式。
D. The use of subsurface floats to map large-scale circulation in the ocean. D. 利用地下漂浮物绘制大规模海洋环流图。
【考查点】推理判断题。
【解题思路】根据题干定位到第三段第四句“在医学断层扫描中，X射线可以绘制出人体密度的变化（以及内部器官），来自X射线的信息，通过身体的许多不同路径传输，被重新组合（recombined），形成身体内部的三维图像（three-dimensional images）”，从中可知，医学断层扫描中，其使用的原理就是通过X射线的扫描，收集身体内部不同器官传输的信息，然后重组形成身体的三维图像，从而来进行医学判断；四个选项中与此原理相似的是B项，因此，该题选择B项正确。
【干扰项排除】
A、C、D选项都不属于层析技术，属于出处错位。
28.【选项释义】
28. The author mentions EI Nino primarily in order to emphasize which of the following points? 28. 作者提到厄尔尼诺主要是为了强调以下哪一点？
A. The brief duration of weather patterns. A. 气候模式的短暂持续时间。
B. The difficulty of measuring the ocean’s large-scale currents. B. 测量海洋大尺度洋流的难度。
C. The effectiveness of low-frequency sound waves in mapping the ocean. C. 低频声波在海洋测绘中的有效性。
D. The possible impact of mesoscale fields on weather conditions. D. 中尺度场对气候状况可能产生的影响。
【考查点】推理判断题。
【解题思路】根据题干定位第二段最后一句“事实上，中尺度现象可能在海洋混合、海气相互作用和偶尔但影响深远的气候事件中，如在影响全球气候模式的赤道太平洋大气-海洋扰动的厄尔尼诺气候事件中，发挥着重要作用”，从中可知，中尺度现象对厄尔尼诺这样的气候事件可以发挥重要的作用，所以推断，作者在这里提到厄尔尼诺是为了强调中尺度现象对气候的影响，D项正确。
【干扰项排除】
A、C选项与题干无关，属于出处错位；
B选项在文中没有提及测量海洋大尺度洋流，该项属于无中生有。
29.【选项释义】
29. Which of the following best describes the organization of the third paragraph of the passage? 29. 下面哪个选项最好地描述了文章第三段的结构？
A. Opposing views are presented, elaborated, and then reconciled. A. 相反的观点被提出，阐述，然后调和。
B. A problem is described, and then a solution is discussed and its effectiveness is affirmed. B. 首先描述了一个问题，然后讨论了解决方案，并肯定了其有效性。
C. An argument is advanced, then refuted, and an alternative is suggested. C. 先提出一个论点，然后反驳，然后提出另一种选择。
D. A hypothesis is presented, qualified, and then reaffirmed. D. 假设被提出，被确认，然后被重新确认。
【考查点】推理判断题。
【解题思路】定位文章第三段，第一句先指出测量中尺度场所存在的问题，即“使用传统技术测量中尺度场是不可行的”，然后在第三句提出了用层析成像技术来测量的方法，然后通过对医学断层扫描举例来做类比，最后得出结论：“他们最初的试验非常成功，海洋声学断层摄影术诞生了”；综上所述，我们可以推断，文章第三段的结构是：提出问题—讨论问题和提出解决办法—证明解决办法的有效性，所以B项正确。
【干扰项排除】A、C、D选项都不符合第三段的结构，属于曲解原文。
30.【选项释义】
30. The passage suggests that which of the following would be true if the ocean’s circulation consisted primarily of large, slow-moving currents? 30. 这篇文章表明，如果海洋环流主要是由大的、移动缓慢的洋流组成，下面哪个选项是正确的？
A. Conventional measuring techniques would be a feasible method of studying the physical properties of the ocean. A. 传统的测量技术将是研究海洋物理特性的可行方法。
B. The influence of mesoscale fields on global weather patterns would remain the same. B. 中尺度场对全球气候模式的影响将保持不变。
C. The majority of the ocean’s kinetic energy would be derived from mesoscale fields. C. 海洋的大部分动能将来自中尺度场。
D. Atmospheric-oceanic disturbances such as EI Nino would occur more often. D. 像厄尔尼诺这样的大气-海洋扰动将更频繁地发生。
【考查点】推理判断题。
【解题思路】文章第一段开头就指出“1965年以前，许多科学家把海洋水团的循环描绘成由大型、缓慢移动的洋流组成的，例如墨西哥湾流”，但是新技术的采用（newly developed techniques and equipment），发现深海中的变化并不是开头所说的那样，如第四句说的“这些仪器（These instruments）揭示了深海中出乎意料的变化水平”；然后随即对中尺度场的测量展开的论述，在第三段第一句提到“使用传统技术测量中尺度场是不可行的”，然后就提出了层析技术。综合推断，我们可以知道，如果海洋环流主要是由大的、移动缓慢的洋流组成，那么使用传统的技术测量海洋物理特性是可行的，所以A项正确。
【干扰项排除】
B、C选项，如果海洋环流是由洋流组成，那么中尺度场就不会被研究，该两项属于曲解原文；
D选项在文中没有表明，中尺度场能阻止厄尔尼诺这样的现象发生，所以属于无中生有。
