82.(33511-!-item-!-188;#058&007598)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 occurred 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.
答案 C 括号里面那句话我读不懂~估计对解题有帮助的。这题我反复看了3遍 还是没弄明白~
-- by 会员 塔罗牌 (2011/7/25 17:52:28)
The meaning of "the threshold of economic viabilityfor solar power " is defined as "price per barrel to which oil would have to risein order for new solar power plants to be more economical than new oil-firedpower plants." In other words, the price of oil at which the power generated by the solar power plant is cheaper that by oil-fired power plants. This is a paradox question, for which you need to provide a clause to explain the discrepancy. C does that. If both the oil-fired and solar-powered plants increase their efficiency, the threshold of economic viability for solar power remains unchanged. -- by 会员 sdcar2010 (2011/7/25 18:59:41)
我还是不怎么明白 就是说用SOLAR POWER的厂的油钱比用OIL FIRED POWER的厂的少~ 那和技术变化引起效率变化 有什么关系啊?? |