7. Traverton's city council wants to minimize the city's average yearly expenditures on its traffic signal lights and so is considering replacing the incandescent bulbs currently in use with arrays of light-emitting diodes (LEDs) as the incandescent bulbs burn out. Compared to incandescent bulbs, LED arrays consume significantly less energy and cost no more to purchase. Moreover, the costs associated with the conversion of existing fixtures so as to accept LED arrays would be minimal. Which of the following would it be most useful to know in determining whether switching to LED arrays would be likely to help minimize Traverton's yearly maintenance costs? (A) Whether the expected service life of LED arrays is at least as long as that of the currently used incandescent bulbs (B) Whether any cities have switched from incandescent lights in their traffic signals to lighting elements other than LED arrays (C) Whether the company from which Traverton currently buys incandescent bulbs for traffic signals also sells LED arrays (D) Whether Traverton's city council plans to increase the number of traffic signal lights in Traverton (E) Whether the crews that currently replace incandescent bulbs in Traverton's traffic signals know how to convert the existing fixtures so as to accept LED arrays
答案是A
我知道E是错误的，明白E为什么不对，但不明白OG的解释： Since the goal of switching to LED arrays is to help minimize yearly expenditures on maintenance , a potential one-time cost—that of training workers to convert the existing fixtures—is not relevant. Further, it is not necessarily the case that the crews that currently replace the incandescent bulbs would be the ones converting the existing fixtures—and even if they were, the account of the plan states that conversion costs would be minimal. OG对E解释说了一大堆，但是原文中的最后一句话不是已经否定了E的concern了吗。 Moreover, the costs associated with the conversion of existing fixtures so as to accept LED arrays would be minimal. 原文已经说了，要换灯泡也是minimal的呀。 难道原文的句子和E说的不是一回事吗？ 求问啊。作者: sheryter 时间: 2012-7-9 16:44
你理解没错，E解释的最后一句也就是你说的意思，一回事情。考试的时候也不可能像OG想那么多的。OG想法可能会更严密一点。