ChaseDream
搜索
返回列表 发新帖
00:00:00

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?

正确答案: C

更多相关帖子

524

帖子

15

好友

4712

积分

ChaseDream

注册时间
2003-03-17
精华
8
解析
查看: 3650|回复: 7

【请教】T-4-Q2

[复制链接]
发表于 2009-7-9 19:08:00 | 显示全部楼层

【请教】T-4-Q2

T-4-Q2      

Twenty years ago, Balzania put in place regulations requiring operators of surface mines to pay for the reclamation(开垦) 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.(矿的总产量也少了啊——总钱数少了,总产量也少了,并不能推出平均每吨成本就少了啊???)

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:C

请各路大侠指教!!!谢谢!!!

发表于 2009-7-10 01:43:00 | 显示全部楼层
注意:the average reclamation cost这句话,实际上是说,在表面开发和其他地方开发的平均费用。如果,在表面开发的成本很高,那么工厂就会去其他地方开发以降低成本。那么,平均开发成本就要低于表面和其他地方同时开发的成本。C选项就是这个意思。
发表于 2009-7-10 17:25:00 | 显示全部楼层
"costs per ton of coal produced are particularly high for mines in such areas"说明山区的平均开发成本高于总平均成本开发成本
总平均成本中较高平均成本的那部分没了,总平均成本不就降低了吗
实在不懂可计算一下,设较高的平均开发成本为8 D/t 占总平均的50%,没撤销高较高开发成本时的总平均开发成本为6D/t,可算得其他的地方平均开发成本为4 D/t,把较高的那部分开发成本去掉,现在的总平均不就变为4 D/t了吗
发表于 2009-7-11 00:19:00 | 显示全部楼层
厉害,edmundshi,你数学太好了。
发表于 2009-10-24 02:10:00 | 显示全部楼层
哦哦哦哦哦哦哦哦~~!!!!我是用排除法做的,比较笨。
发表于 2010-3-22 22:18:51 | 显示全部楼层
thx
发表于 2010-7-9 16:51:09 | 显示全部楼层
我选了B ,咔咔~~~我发现我越想越复杂,但B也有道理哦
发表于 2012-3-22 22:33:47 | 显示全部楼层
同意ls  经济学不是这样的么  需求越少了 不是价格会下降么
您需要登录后才可以回帖 登录 | 立即注册

Mark一下! 看一下! 顶楼主! 感谢分享! 快速回复:

手机版|ChaseDream|GMT+8, 2024-3-29 06:42
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号

ChaseDream 论坛

© 2003-2023 ChaseDream.com. All Rights Reserved.

返回顶部