[求助] tpo8-3阅读求助 [复制链接]

coolsheva
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电梯直达

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发表于 2012-9-23 18:20:37 |只看该作者 |倒序浏览

TPO8 RUNNING WATER ON MARS

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.

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.

答案是c，但是a和d也不对啊。
与a对应的是最后一句，但文中的时间点是火山平原形成的时间，而a选项是火山活动的时间。
与d对应的是draining from the southern highlands into the northern plains，并不是 northward from the equatorial regions。
求大神指导，顺便解释一下选项c的意思。

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black_marble
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沙发

发表于 2012-9-23 19:07:23 |只看该作者

对于A选项，volcanic activity 导致了volcanic plains 的形成。所以是对的，具体是这样的，火山会喷发出熔岩，就像水一样溢流，冷却了就形成了volcanic plains。

D选项应该是对的，They appear only in equatorial regions ，draining from the southern highlands into the northern plains.这两个加起来应该说的就是northward 不过对于from the equatorial regions我也有点疑问。

对于C选项，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.
意思应该是说它们有时会倾倒到一些看上去曾经是潮滩上的湿沙的地方

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