我又不请自来了, 觉得GMAT很多经济问题说得没头没尾的, 向你请教, 3Q 153、Technological improvements and reduced equipment costs have made converting solar energy directly into electricity far more cost-efficient in the last decade.However, the threshold of economic viability for solar power(that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars. Which of the following,if true,does most to help explain why the increased cost-efficiency of solar power has not decreased its threshold of economic viability? A) The cost of oil has fallen dramatically. B)The reduction in the cost of solar-power equipment has occured despite increased raw material costs for that equipment. C)Technological changes have increased the efficiency of oil-fired,power plants. D)Most electricity is generated by coal-fired or nuclear,rather than oil-fired,power plants. E)When the price of oil increases, reserves of oil not previously worth exploiting become economically viable
很多人是这样理解的,可是我觉得 the threshold of economic viability 推不出以下的等式, 当油价为35时,太阳能电和火力电价格持平,即: 太阳能cost=35+火力cost,太阳能cost-火力cost=35,当太阳能cost下降时, 等式继续成立,所以火力cost必然下降,这里与油价没有关系。 而我认为文中只能知道他们是同向变话的关系:临界问题: SOLAR –cost –efficient.. 必须OIL – cost efficient … 所以他们的临界值才可能不变。 临界问题: SOLAR –cost –efficient.. 必须OIL – cost efficient … 所以他们的临界值才可能不变。
[此贴子已经被作者于2006-5-25 17:39:11编辑过] |