GWD--TN--15--3

zhongyaya

Highway Official:  When resurfacing our concrete bridges, we should use electrically conductive concrete (ECC) rather than standard concrete.  In the winter, ECC can be heated by passing an electric current through it, thereby preventing ice buildup.  The cost of the electricity needed is substantially loiwer than the cost of the deicing salt we currently use.

Taxpayer:  But construction costs for ECC are much higher than for standard concrete, so your proposal is probably not justifiable on economic grounds.

Which of the following, if true, could best be used to support the highway official’s proposal in the face of the taxpayer’s objection?



A.      The use of de-icing salt causes corrosion of the reinforcing steel in concrete bridge decks and damage to the concrete itself, thereby considerably shortening the useful life of concrete bridges.

B.      Severe icing conditions can cause power outages and slow down the work of emergency crews trying to get power restored. ir

C.      In weather conditions conducive to icing, ice generally forms on the concrete surfaces of bridges well before it forms on parts of the roadway that go over solid ground.

D.      Aside from its potential use for de-icing bridges, ECC might also be an effective means of keeping other concrete structures such as parking garages and airport runways ice free.

E.       If ECC were to be used for a bridge surface, the electric current would be turned on only at times at which ice was likely to form.

本题答案选A~请帮忙看下，这题D应该是无关选项吧？

zhongyaya

顶~

echo0709

D选项显然是无关的选项 本题是在谈成本 说白了就是在说钱的问题 D选项说ECC还有其他的好处但是没有说钱这是在明显的回避本题（反对者）的反对点 当然不对 而A选项则是正好说了这一点 她说原来的那个方法会极大的减少桥的寿命 显然是在说这样会导致更加的大的花费了 因此是有力的反驳了反对者的立场

zhongyaya

嗯~谢谢解答