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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 amount 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?
- AThe cost of magnesium carbonate, currently greater than the cost of calcium carbonate, probably will fall as more magnesium carbonate is used in cement manufacture.
- BEco-cement is strengthened when absorbed carbon dioxide reacts with the cement.
- CBefore the development of eco-cement, magnesium-based cement was considered too susceptible to water erosion to be of practical use.
- DThe manufacture of eco-cement uses considerably less fossil fuel per unit of cement than the manufacture of conventional cement does.
- EMost building-industry groups are unaware of the development or vailability of eco-cement.
- 一直在BD两个选项里面纠结，D选项正确的原因我理解了
- 关于B选项，我自己的理解是重复前提
- OG的解释是即使吸收了二氧化碳变硬，eco-cement不一定能作为广泛运用的建筑材料，更谈不上减少二氧化碳了
- 我自己觉得OG的解释确实是有道理，但是不知道怎么归这一类的错误（OG的的解释总让我觉得它是在根据具体情况破案，不是在做题哈哈哈）另外感觉平常自己做题想不到这个点，想问问大神们是缺乏练习吗，
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发表于 2019-11-4 12:20:28
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