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标题: 天山-04套-02题 [打印本页]

作者: hakoolulu 时间: 2005-2-19 15:45
标题: 天山-04套-02题
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.

作者: beautywawa 时间: 2005-2-19 23:35

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