逻辑T-4-Q2

footprintkp

Twenty years ago, Balzania put in place regulations requiring operators of surface mines to pay for the reclamation of mined-out land. Since then, reclamation technology has not improved. Yet, the average reclamation cost for a surface coal mine being reclaimed today is only four dollars per ton of coal that the mine produced, less than half what it cost to reclaim surface mines in the years immediately after the regulations took effect.
Which of the following, if true, most helps to account for the drop in reclamation costs described?
A.    Even after Balzania began requiring surface mine operators to pay reclamation costs, coal mines in Balzania continued to be less expensive to operate than coal mines in almost any other country.
B.    In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.
C.    Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.
D.    Even after Balzania began requiring surface mine operators to pay reclamation costs, surface mines continued to produce coal at a lower total cost than underground mines.
E.    As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.

答案是c，我选的e，我的思路是 总的cost/总的ton 下降了，没有新技术开发，可以认为总的cost不变，那就是总的ton上升了，所以选了e。。
这个c是个啥意思呢，想不明白，请nn们指教！！
谢谢！！

panbangzhu

这个题目的PARADOX主要是，这个方案都提了20年，但是reclamation的技术0提高，而且加之相比起来，费用减少了一半。

中你认为greater percentage就以为着greater quantity是不正确的，逻辑中经常这样考，属于你主观想象。

而C中不需要你添加主观想象，可以解答题目中的paradox。因为即使现在的价格是之前的一半，也不表明是便宜。

另外，E中的观点，对技术0提高的联系，不如C中强，C中直接讲不在这些地方采集了，那么必然是0提高。

footprintkp

谢谢你！！！

hjbb1027

我把c理解为，被迫离开市场的都是高成本的，留下的都是低成本的，所以成本降低了

YEWCHOW

我是这么理解的：政府的目的是通过收取reclamation增加收入、同时保护矿区，那么自然是挖的多这种类似与罚款性质的费用就应该越高，否则就失去了保护的意义；而技术没有变化只是排除了其他因素影响价格的可能性，这样，这个reclamation fee在二十年之后不升反降，只能说明来这里挖煤的人少了，而不应该是多了。所以其他几项都不可能产生联系，E项说通过这种方式挖出的煤更多了，那样fee应该升高，而非下降，只剩下BC，我认为，B之所以错是因为没有突出B国的情况，而成了概述。等待NN解答

interlove11

B.    In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.

B 成立需要加主观想象
煤作为燃料的使用减少了又怎样？这与人少使用煤有gap