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41. Since the mayor’s publicity campaign for Greenville’s bus service began six months ago, morning automobile traffic into the midtown area of the city has decreased seven percent. During the same period, there has been an equivalent rise in the number of persons riding buses into the midtown area. Obviously, the mayor’s publicity campaign has convinced many people to leave their cars at home and ride the bus to work.
Which of the following, if true, casts the most serious doubt on the conclusion drawn above? A. Fares for all bus routes in Greenville have risen an average of five percent during the past six months. B. The mayor of Greenville rides the bus to City Hall in the city’s midtown area.
C. Roadreconstruction has greatly reduced the number of lanes available to commuters in major streets leading to the midtown area during the past six months.D. The number of buses entering the midtown area of Greenville during the morning hours is exactly the same now as it was one year ago.
C E. Surveys show that longtime bus riders are no more satisfied with the Greenville bus service than they were before the mayor’s publicity campaign began.
A eliminates decreased fares as a possible explanation for the increased ridership, so it supports rather than casts doubt on the conclusion. The fact that the mayor rides the bus, cited in B, may contribute to the effectiveness of the publicity campaign, but it is irrelevant to assessing whether the campaign caused the increased ridership. D eliminates a possible explanation-that the increased ridership is a result of extra buses-and thus supports the conclusion rather than casts doubt on it. E eliminates a possible explanation-that the increased ridership is a result of improved service-and thus supports the conclusion rather than casts doubt on it. 答案是C 我犹豫在C&D之间 C 是他因削弱 我觉得D也是他因 说明这段时间坐车人数增加是周期性导致的 并不能说明是the mayor’s publicity campaign 导致的结果呀 请各位指教
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发表于 2007-10-10 02:11:00
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