OG17-592

xiaosais

592. Many industrialized nations are trying to reduce atmospheric concentrations of carbon dioxide, a gas released by the burning of fossil fuels. One proposal is to replace conventional cement, which is made with calcium carbonate, by a new “eco-cement.” This new cement, made with magnesium carbonate, absorbs large amounts of carbon dioxide when exposed to the atmosphere. Therefore, using eco-cement for new concrete building projects will significantly help reduce atmospheric concentrations of carbon dioxide.

Which of the following, if true, most strengthens the argument?

(A)   The cost of magnesium carbonate, currently greater than the cost of calcium carbonate, probably will fall as more magnesium carbonate is used in cement manufacture.
(B)   Eco-cement is strengthened when absorbed carbon dioxide reacts with the cement.
(C)   Before the development of eco-cement, magnesium-based cement was considered too susceptible to water erosion to be of practical use.
(D)   The manufacture of eco-cement uses considerably less fossil fuel per unit of cement than the manufacture of conventional cement does.
(E)   Most building-industry groups are unaware of the development or availability of eco-cement.

我想问一下B为啥不行？另外B中最后的the cement指的是co-cement还是普通的cement呢？
这个选项好凌乱。。。。

Fiona09

题目中是说新旧方法的对照，旧方法：传统水泥制法——用碳酸钙；新方法：用碳酸镁制造水泥，碳酸镁能够在接触到空气的时候吸收大量二氧化碳。

结论：在建筑工程中使用新型水泥能够显著降低空气中的二氧化碳含量。

要求加强，也就是进一步说明新方法相较于旧方法在环保方面的优越性。

而B项是说新水泥吸收的二氧化碳会和水泥发生反应起到加固作用，但是和是否能降低二氧化碳含量并无直接关系。