托福TPO解析TPO8 Running Water on Mars

Paragraph 1 1. The word merge in the passage is closest in meaning to ○expand ○separate ○straighten out ○combine 2. What does the discussion in paragraph 1 of runoff channels in the southern highlands suggest about Mars? ○The atmosphere of Mars was once thinner than it is today. ○Large amounts of rain once fell on parts of Mars. ○The river systems of Mars were once more extensive than Earth’s. ○The rivers of Mars began to dry up about 4 billion years ago. Paragraph 2 3. The word relics in the passage is closest in meaning to ○remains ○sites ○requirements ○sources 4. The word miniature in the passage is closest in meaning to ○temporary ○small ○multiple ○familiar 5. In paragraph 2, why does the author include the information that 105 tons of water flow through the Amazon river per second? ○To emphasize the great size of the volume of water that seems to have flowed through Mars’ outflow channels ○To indicate data used by scientists to estimate how long ago Mars’ outflow channels were formed ○To argue that flash floods on Mars may have been powerful enough to cause tear-shaped “islands” to form ○To argue that the force of flood waters on Mars was powerful enough to shape the northern volcanic plains 6. According to paragraph 2, all of the following are true of the outflow channels on Mars EXCEPT: ○They formed at around the same time that volcanic activity was occurring on the northern plains. ○They are found only on certain parts of the Martian surface. ○They sometimes empty onto what appear to have once been the wet sands of tidal beaches. ○They are thought to have carried water northward from the equatorial regions. Paragraph 3 7. All of the following questions about geological features on Mars are answered in paragraph 3 EXCEPT: ○What are some regions of Mars that may have once been covered with an ocean? ○Where do mission scientists believe that the river forming the delta emptied? ○Approximately how many craters on Mars do mission scientists believe may once have been lakes filled with water? ○During what period of Mars’ history do some scientists think it may have had large bodies of water? 8. According to paragraph 3, images of Mars’ surface have been interpreted as support for the idea that ○the polar regions of Mars were once more extensive than they are now ○a large part of the northern lowlands may once have been under water ○deltas were once a common feature of the Martian landscape ○the shape of the Hellas Basin has changed considerably over time Paragraph 4 9. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information. ○But detractors argue that geological activity may be responsible for the water associated with the terraces. ○But detractors argue that the terraces may have been formed by geological activity rather than by the presence of water. ○But detractors argue that the terraces may be related to geological forces in the Northern Hemisphere of Mars, rather than to Martian water in the south. ○But detractors argue that geological forces depressed the Northern Hemisphere so far below the level of the south that the terraces could not have been formed by water. 10. According to paragraph 4, what do the 2003 Global Surveyor data suggest About Mars? ○Ancient oceans on Mars contained only small amounts of carbon. ○The climate of Mars may not have been suitable for the formation of large bodies of water. ○Liquid water may have existed on some parts of Mars’ surface for long periods of time. ○The ancient oceans that formed on Mars dried up during periods of cold, dry weather. Paragraph 5 11. The word hints in the passage is closest in meaning to ○clues ○features ○arguments ○effects Paragraph 2 12. Look at the four squares [■] that indicate where the following sentence could be added to the passage. These landscape features differ from runoff channels in a number of ways. Where would the sentence best fit? 13. Directions: An introductory sentence for a brief summary of the passage is provided below. 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 that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. There is much debate concerning whether Mars once had water. · · · Answer choices 1. Mars’ runoff and outflow channels are large-scale, distinctive features that suggest that large quantities of liquid water once flowed on Mars. 2. Although some researchers claim that Mars may once have had oceans, others dispute this, pointing to an absence of evidence or offering alternative interpretations of evidence. 3. Various types of images have been used to demonstrate that most of Martian surface contains evidence of flowing water. 4. The runoff and outflow channels of Mars apparently carried a higher volume of water and formed more extensive networks than do Earth’s river systems. 5. There is very little evidence of liquid water on Mars today, and it is assumed that all the water that once existed on the planet is frozen beneath its surface. 6. While numerous gullies have been discovered on Mars since 2000, many astronomers dismiss them as evidence that Mars once had liquid water. RUNNING WATER ON MARS Photographic evidence suggests that liquid water once existed in great quantity on the surface of Mars. Two types of flow features are seen: runoff channels and outflow channels. Runoff channels are found in the southern highlands. These flow features are extensive systems―sometimes hundreds of kilometers in total length―of interconnecting, twisting channels that seem to merge into larger, wider channels. They bear a strong resemblance to river systems on Earth, and geologists think that they are dried-up beds of long-gone rivers that once carried rainfall on Mars from the mountains down into the valleys. Runoff channels on Mars speak of a time 4 billion years ago (the age of the Martian highlands), when the atmosphere was thicker, the surface warmer, and liquid water widespread. Outflow channels are probably relics of catastrophic flooding on Mars long ago. ■They appear only in equatorial regions and generally do not form extensive interconnected networks. ■Instead, they are probably the paths taken by huge volumes of water draining from the southern highlands into the northern plains. ■The onrushing water arising from these flash floods likely also formed the odd teardrop-shaped “islands” (resembling the miniature versions seen in the wet sand of our beaches at low tide) that have been found on the plains close to the ends of the outflow channels. ■Judging from the width and depth of the channels, the flow rates must have been truly enormous―perhaps as much as a hundred times greater than the 105 tons per second carried by the great Amazon river. Flooding shaped the outflow channels approximately 3 billion years ago, about the same times as the northern volcanic plains formed. Some scientists speculate that Mars may have enjoyed an extended early Period during which rivers, lakes, and perhaps even oceans adorned its surface. A 2003 Mars Global Surveyor image shows what mission specialists think may be a delta―a fan-shaped network of channels and sediments where a river once flowed into a larger body of water, in this case a lake filling a crater in the southern highlands. Other researchers go even further, suggesting that the data provide evidence for large open expenses of water on the early Martian surface. A computer-generated view of the Martian north polar region shows the extent of what may have been an ancient ocean covering much of the northern lowlands. The Hellas Basin, which measures some 3,000 kilometers across and has a floor that lies nearly 9 kilometers below the basin’s rim, is another candidate for an ancient Martian sea. These ideas remain controversial. Proponents point to features such as the terraced “beaches” shown in one image, which could conceivably have been left behind as a lake or ocean evaporated and the shoreline receded. But detractors maintain that the terraces could also have been created by geological activity, perhaps related to the geologic forces that depressed the Northern Hemisphere far below the level of the south, in which case they have nothing whatever to do with Martian water. Furthermore, Mars Global Surveyor data released in 2003 seem to indicate that the Martian surface contains too few carbonate rock layers―layers containing compounds of carbon and oxygen―that should have been formed in abundance in an ancient ocean. Their absence supports the picture of a cold, dry Mars that never experienced the extended mild period required to form lakes and oceans. However, more recent data imply that at least some parts of the planet did in fact experience long periods in the past during which liquid water existed on the surface. Aside from some small-scale gullies (channels) found since2000, which are inconclusive, astronomers have no direct evidence for liquid water anywhere on the surface of Mars today, and the amount of water vapor in the Martian atmosphere is tiny. Yet even setting aside the unproven hints of ancient oceans, the extent of the past. Where did all the water go? The answer may be that virtually all the water on Mars is now locked in the permafrost layer under the surface, with more contained in the planet’s polar caps. TPO8 Running Water on Mars 1. 与单词merge在文中意思最接近的是 （Vocabulary Question） a) Expand （膨胀） b) Separate （分离） c) Straighten out （理顺） d) Combine （结合） 解析：merge：to combine or join together；释义来自剑桥高级学习词典； 2. 第一段对南部高地runoff河道的讨论明了关于火星的哪个方面？ （Factual Information Question） a) 火星的大气曾今比现在要薄。 b) 火星部分地区有大量降雨。 c) 火星的河流系统曾今比地球还广泛。 d) 火星的河流在大约40亿年前开始干涸。 解析：段落倒数第二句“……geologists think that they are dried-up beds of long-gone rivers that once carried rainfall on Mars from the mountains down into the valleys,……”意思是：地质学家认为它们是已经干涸的河流，这些河流曾今把降雨从山区带到峡谷。 3. 与单词relics在文中意思最接近的是 （Vocabulary Question） a) Remains （残留物） b) Sites （遗址） c) Requirements （要求） d) Sources （源头） 解析：relics n.遗物，遗骸； 4. 与单词miniature在文中意思最接近的是 （Vocabulary Question） a) Temporary （临时的） b) Small （小的） c) Multiple （多样的） d) Familiar （熟悉的） 解析：Miniature is used to describe something which is very small, especially a smaller version of something which is normally much bigger. 释义来自柯林斯高级学习词典。 Miniature n.小型的，微小的； 5. 第二段中，为什么作者要提到亚马逊河每秒钟的流量是105吨？ （Rhetorical Purpose Question） a) 强调曾今在火星outflow河道流过巨大的水量。 b) 指出科学家用来估计火星outflow河道在多久之前形成的数据。 c) 认为火星山洪爆发（flash floods）可能非常给力导致了泪眼状岛屿的形成。 d) 认为火星洪水非常给力导致了北部火山平原的形成。 解析：回到原句“Judging from the width and depth of the channels, the flow rates must have been truly enormous-perhaps as much as a hundred times greater than the 105 tons per second carried by the grate Amazon river.”意思是：通过河道的宽度和深度判断，流水速率肯定非常大——也许是亚马逊河流每秒105吨流量的一百多倍。这句话做的对比明显就是要突出火星outflow河道的巨大流量。 6. 根据第二段，以下哪项关于火星outflow河道是不正确的？ （Negative Factual Information Question） a) 它们形成的时间大约与北部平原发生火上运动的时间相同。 b) 它们只在火星表面的某些部分被发现。 c) 它们有时会朝那些看起来可能是潮汐沙滩的地方倒空。 d) 它们被认为带着水从赤道地区朝北流动。 解析：选项一对，段落最后一句“Flooding shaped the outflow channels approximately 3 billion years ago, about the same times as the northern volcanic plains formed.”意思是：洪水在大约30亿年前塑造了outflow河道，与北方火山平原的形成处在大约同一时间。选项二对，段落第二句话“They appear only in equatorial regions and generally do not form extensive interconnected networks.”意思是：它们只出现在赤道地区并且通常不会形成广泛互联的网络。选项四正确，段落第三句“Instead, they are probably the paths taken by huge volumes of water draining from the southern highlands into the northern plains.”意思是：它们很可能是大量从南方高地到北方平原的大量水所进过的路线。因为第二句话说了它们只出现在赤道地区，然后第三句话说这是从南方到北方的水流会经过的路线，所以选项四说从赤道地区到北方也是可以的。选项三就错了，段落第四句“The onrushing water arising from these flash floods likely also formed the odd teardrop-shaped ‘islands’……”意思是：汹涌澎湃的洪水很可能会形成奇怪的泪眼状岛屿……；没有提到会把水往潮汐沙滩倒空。所以选项三错误。 7. 以下哪个关于火星地质特征的问没有在第三段中得到回答？ （Negative Factual Information Question） a) 火星哪些地方可能曾今被海洋覆盖？ b) 科学家们认为形成三角洲的河流在哪里干涸？ c) 科学家认为火星上大约有多少坑曾今是充满水的湖？ d) 科学家认为在火星的什么时期可能有大片水域？ 解析：到文章里面找数字，发现只有年份（2003）和直径（3,000），就是没找到有多少个坑。那么明显选项三的问题就没有回答。段落最后一句提到了Hellas Basin可能是被海洋覆盖的，所以选项一的问题有回答。段落第二句最后部分提到southern highlands，所以选项二的问题也有回答。段落第一句提到early period，也算是回答了选项四的问题。 8. 根据第三段，火星表面的图像被认为支持以下哪种想法？ （Factual Information Question） a) 火星极地地区曾今比现在要更广泛。 b) 北部低地大部分曾今是处于水下。 c) 三角洲曾今是火星地表的一个常见特色。 d) Hellas Basin的形状随着时间发生了重大改变。 解析：段落倒数第二句“A computer-generated view of the Martian north polar region shows the extent of what may have been an ancient ocean covering much of the northern lowlands.”意思是：电脑生成的对火星北极地区的视角图显示曾今覆盖了大部分北部低地的古老海洋的范围。所以选项二正确。 9. 以下哪一项能表达出高亮句子的精华核心含义？错误选项改变重要含义或者遗漏精华信息。 But detractors maintain that the terraces could also have been created by geological activity, perhaps related to the geologic forces that depressed the Northern Hemisphere far below the level of the south, in which case they have nothing whatever to do with Martian water. 但是贬损此意见的人认为梯田形状很可能是地质运动形成的，也许是地质力量把北半球压到比南部水平更低的地方。如果是这样的话，它们（梯田）就和火星水毫无关系了。 a) 但是贬损此意见的人认为地质运动才是与造成梯田有关的水的原因。 b) 但是贬损此意见的人认为是地质运动形成的梯田而不是水的出现形成了梯田。 c) 但是贬损此意见的人认为梯田可能和火星北半球的地址力量有关，而不是与火星南部的水有关。 d) 但是贬损此意见的人认为地质运动是的北半球下陷到南部水平面以下太多导致梯田不可能是由水形成的 10. 根据第四段，2003年Global Surveyor的数据显示了什么关于火星的信息？（Factual Information Question） a) 火星的古老海洋只包含少量碳。 b) 火星的气候可能不适合大量水域的形成。 c) 液态水可能在一段时间存在于火星某些地方。 d) 火星上形成的古老海洋在阴冷干燥的气候下干涸了。 解析：段落第四句“Furthermore, Mars Global Surveyor data released in 2003 seem to indicate that the Martian surface contains too few carbonate rock layers – layers containing compounds of carbon and oxygen – that should have been formed in abundance in an ancient ocean.”意思是：不仅如此，火星的Global Surveyor在2003年放出的数据好像显示出火星表面碳酸盐岩石层（包含碳氧化合物的层）太少了，而古老海洋中应该会形成很多碳酸盐岩石。第五句“Their absence supports the picture of a cold, dry Mars that never experiencedthe extended mild period required to form lakes and oceans.”意思是：他们的缺席证明了一个冰冷干燥火星。这个火星从未经历过广泛温时期也为形成湖泊和海洋的。所以选项二是正确。 11. 与单词hints在文中意思最接近的是 （Vocabulary Question） a) Clues （线索） b) Features （特点） c) Arguments （论点） d) Effects （效果） 解析：hint n.暗示； 12. Look at the four squares ■that indicate where the following sentence could be added to the passage. These landscape features differ from runoff channels in a number of ways. 这些地貌特征runoff河道在很多方面都有不同。 解析：解题的关键在于these landscape features，in a number of ways。回到原文，发现第一句话引入outflow，之后全部是讲的outflow与runoff的区别，所以答案明显是第一个插入口。 13. There is much debate concerning whether Mars once had water. 关于火星上曾今是否有水有很多争论。 a) 火星上的runoff和outflow河道都是大范围的并拥有明显的特点表明火星上曾今流动着大量的液体水。 b) 尽管一些研究者声称火星可能曾今有海洋，其他人对此有异议，指出缺乏证据或者提供对证据的另外一种解释。 c) 多种不同的图像被用来证明火星表面很大一部分含有流水的证据。 d) 火星的runoff和outflow河道明显水流量比地球的河流系统大，而且形成的网络也更广泛。 e) 现在几乎没有证据可以证明火星上有液态水，而且假设认为所有曾今存在于星球上的水都被冰冻在表面之下。 f) 自从2000年以来火星上发现大量的峡谷，很多天文学家不认为它们是火星上曾今存在水的证据。 解析：选项一对，第一段和第二段的主要内容； 选项二对，第四段的主要内容； 选项三错，只有第三段的2003Mars Global Surveyor的图像被用来证明火星上有水，并没有多种多样的图像； 选项四错，没有做过此类的比较，文章只是在第二段比较了河道而已，但是并没有比较runoff的网络； 选项五对，第五段的主要内容； 选项六错，第五段第一句就说只有small-scale gullies，而且也没有说过astronomer dismiss them，所以与内容相悖； 因此，答案是：1,2,5；