Highway Official: When resurfacing our concrete bridges, we should use electrically conductive concr...

题目信息

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 lower than the cost of the de-icing 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.

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.

参考答案及共享解析

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正确答案： 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.

题目类型：增强题

题目场景：

高速路管理局：当翻修混凝土桥时，我们应该使用ECC（可导电的混凝土）来代替普通混凝土。因为在冬天，ECC可以通过导电而产生热量从而融化路面的冰。且需要的电费比我们现在撒盐融雪的费用低很多。

纳税人：但是ECC要比普通混凝土贵很多，因此你的建议在经济意义上并不可行

问下列哪一选项如果为真能够最大程度上支持管理局的意见而反对纳税人的意见

题目推理：

考虑下列哪一选项会导致ECC/普通混凝土产生其他的间接、长期的费用。这样两个选择的费用就变成混凝土费+融冰费用+维修保养费用，从而使得总的成本更高

选项分析：

A.用盐融冰会导致混凝土桥的加固钢铁被腐蚀同时也会损害混凝土桥本身，因此该种桥的使用寿命被缩短。正确选项，重新建一座桥的费用会是一笔很大的开支，因此通过点出普通混凝土桥容易受损寿命短从而使得其总成本会比ECC桥成本高。

B.严重雪灾会导致停电并且延误电力工作人员的维修时间。无关选项。极端天气可以通过使用备用电力设备或者撒盐来解决，该选项并未提出ECC桥伴随的额外费用

C.在容易结冰的天气条件下，通常在桥梁的混凝土表面上会结冰，然后才在道路上经过坚固地面的部分上结冰。这反而会进一步论证防止桥结冰的重要性，而这正是使用ECC的有利论据

D.除了能够帮助桥梁除冰，ECC还能够帮助其他混凝土结构如停车场和机场免受结冰困扰。这也是阐述的ECC的好处