Traverton’s city council wants to minimize the city’s average yearly expenditures on its traffi c 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 signifi cantly less energy
and cost no more to purchase. Moreover, the costs associated with the conversion of existing fi xtures 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
l
ikely 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 traffi c signals to lighting elements other
than LED arrays
(C) Whether the company from which Traverton currently buys incandescent bulbs for traffi c signals also sells
LED arrays
(D) Whether Traverton’s city council plans to increase the number of traffi c signal lights in Traverton
(E) Whether the crews that currently replace incandescent bulbs in Traverton’s traffi c signals know how to
convert the existing fi xtures so as to accept LED arrays
不太看得明白OG上对D的解释，
OG是这样说的
D： Increasing the number of traffi c signal lights in Traverton would probably increase the city’s
yearly maintenance costs, but it would do so regardless of whether those lights use LEDs or
incandescent bulbs
我在想D错误是不是因为他加了附加的条件上去，而且即使是要increase the number of traffic signal lights 那么用LED也比用incandescent bulbs更节约？？作者: justabeginning 时间: 2012-10-8 20:11
我觉得这就是个单纯的无关选项呀……
或者你也可以这么看，如果回答no,即使city council 没有增加traffic light也不能达到削弱结论即：LED不能降低成本。
所以这个选项是错误的。
