题目出处:tpo 8 题目原文: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. 题目选项: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 题目答案:4 疑问所在:我选的1,没看出来是在强调volume啊~ 明明是在说速度哇~ -- by 会员 ctomoyo (2010/8/22 16:28:48)
我最开始也是在A\D纠结,于是又返回去读,发现about the same times as the northern volcanic plains formed.觉得好像不能直接说flood waters shape the northern volcanic plains.所以觉得还是选A好了。 |