托福TPO8閱讀真題文本及參考答案Part3

　　TPO對(duì)于我們的托福備考非常有用，大家還在苦于找不到資料嗎？下面小編給大家?guī)硗懈PO8閱讀真題文本及參考答案Part3，希望可以幫助到你們。

托福TPO8閱讀真題文本Part3

　　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 since 2000, 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 outflow channels suggests that a huge total volume of water existed on Mars in 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.

　　Paragraph 1: 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.

　　托福TPO8閱讀真題題目Part3

　　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: 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.

　　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: 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.

　　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: 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.

　　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.

　　○B(yǎng)ut detractors argue that geological activity may be responsible for the water associated with the terraces.

　　○B(yǎng)ut detractors argue that the terraces may have been formed by geological activity rather than by the presence of water.

　　○B(yǎng)ut 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.

　　○B(yǎng)ut 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: Aside from some small-scale gullies (channels) found since 2000, 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 outflow channels suggests that a huge total volume of water existed on Mars in 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.

　　11. The word "hints" in the passage is closest in meaning to

　　○ clues

　　○ features

　　○ arguments

　　○ effects

　　Paragraph 2: 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.

　　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

　　○Mars' runoff and outflow channels are large-scale, distinctive features that suggest that large quantities of liquid water once flowed on Mars.

　　○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.

　　○Various types of images have been used to demonstrate that most of Martian surface contains evidence of flowing water.

　　○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.

　　○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.

　　○While numerous gullies have been discovered on Mars since 2000, many astronomers dismiss them as evidence that Mars once had liquid water

　　托福TPO8閱讀真題答案Part3

　　參考答案：

　　1. ○4

　　2. ○2

　　3. ○1

　　4. ○2

　　5. ○1

　　6. ○3

　　7. ○3

　　8.○2

　　9. ○2

　　10. ○2

　　11. ○1

　　12. ○1

　　13. Mars' runoff and outflow channels

　　Although some researchers claim

　　There is very little evidence of

　　托福TPO8閱讀真題翻譯：Part3

　　參考翻譯：火星上的流水

　　來自照片的證據(jù)顯示在火星的表面曾有過大量的液態(tài)水。兩種流動(dòng)形式已經(jīng)被發(fā)現(xiàn)：徑流通道和外流通道。徑流通道發(fā)現(xiàn)于南部的高地。這些流動(dòng)形式有著龐大的系統(tǒng)--有時(shí)竟有數(shù)百千米長--這些通道相互交錯(cuò)、扭轉(zhuǎn)，并可能匯入更大更寬的通道中。它們和地球上的河流系統(tǒng)非常相似，地質(zhì)學(xué)家們認(rèn)為它們是以前曾將火星上的雨水從高山攜帶到峽谷中的那些河流干涸后的遺跡。火星上的徑流通道存在于40億年以前(就是火星高地的年齡)，那時(shí)候火星的大氣層更厚，地表更暖和，并且液態(tài)水分布很廣。

　　外流通道可能是很久以前火星上洪災(zāi)的遺跡。它們只形成于赤道附近，并一般沒有形成廣泛的交錯(cuò)的網(wǎng)絡(luò)。相反，它們可能是攜帶大量水從南部高地到北部平原的排水系統(tǒng)。由泛濫的洪水而產(chǎn)生的激流可能也形成奇怪的淚滴狀小島(就像是在低潮時(shí)濕沙地或海灘上看到的縮小版本一樣)，已經(jīng)在靠近出流通道末尾處的平原上被看到。從這些通道的寬度和深度可判斷，當(dāng)時(shí)流速一定很大--有可能是亞馬遜河的每秒鐘105噸的流量的一百多倍。大約在30億年以前，北部火山平原形成的同時(shí)，洪水改變了外流通道的形狀。

　　一些科學(xué)家認(rèn)為早期的火星上廣泛存在著河流，湖泊甚至是海洋。一份2003年的對(duì)火星全球的調(diào)查照片顯示了一個(gè)科學(xué)家們認(rèn)為是三角洲的構(gòu)造--一個(gè)扇形的沉積物和水流通道的網(wǎng)絡(luò)，河流可能是從這里流入了一個(gè)更大的水體;在這種情況下，它可能是南部高地的一個(gè)火山口湖泊。其他研究者做了更大膽的猜測，他們認(rèn)為那些數(shù)據(jù)表明早期在火星表面存在大量的水。一張關(guān)于火星北部極地地區(qū)的電腦圖片說明有可能有一個(gè)古老的海洋覆蓋了大部分北部的低洼處。那座有大約3 000公里寬，9公里深的希臘盆地也可能是火星海洋。

　　這些觀點(diǎn)仍然有爭議。支持者們指出照片里顯示的臺(tái)地"海灘"可以是由湖泊或者海洋蒸發(fā)干涸之后或者海退之后形成的。但是反對(duì)者認(rèn)為這些臺(tái)地也可能是由于地質(zhì)活動(dòng)造成的，也許與使得北半球比南半球地勢更低的地質(zhì)力量有關(guān)，在這種情況下，它們就和火星水系沒有任何關(guān)系。而且，2003發(fā)布的火星全球調(diào)查數(shù)據(jù)也表明火星表面含有太少的碳化巖層--含有碳氧化合物的巖層--它們應(yīng)該是在古代海洋中大量形成的。這些巖層的缺失支持了火星是一個(gè)又冷又干燥的星球這一說法，并且不可能擁有形成湖泊和海洋的溫和氣候。然而，更新的數(shù)據(jù)表明至少該星球上的一些部分表面的確在過去的很長時(shí)間內(nèi)存在液態(tài)水。

　　除了在2000年發(fā)現(xiàn)了一些小規(guī)模的、不確定的溪谷以外，宇航員到目前為止還沒有在星球的什么地方找到液態(tài)水存在的直接證據(jù)。而且火星大氣中的水蒸氣的含量也是微乎其微的。然而就算不考慮尚未證明的古代海洋存在的觀點(diǎn)，出流通道的廣泛存在就足以證明在火星上曾有大量的水體，水都去了哪里呢?答案可能是火星上所有的水實(shí)際上現(xiàn)在已經(jīng)封存在其地下的永久凍層中，并且在極地地區(qū)最多。

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