请教OG-153

michelle84

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
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.

这道题我对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)理解得不是很清楚，请大家指点，正确答案是第3个

fredshen

Cost-efficiency of solar power converting to electricity is measured by the cost of using oil. That is for same amount electricity how much it would cost to generate using oil versus using solar power. The argument presents a paradox that the cost efficiency of solar power is dropping, but its economic vibilty isnt changed. We can safely conclude that the reason for such paradox is becuase of the efficiency of using oil is also improving. Because, the same amount of oil can generate more eletricity now than before, which offsets the cost reduction of solar power.   

babydevil

但我们也可以认为答案A:油更便宜了，单位资金可以获得比以前更多的油从而发出更多的电。发出同样的电量由于油价下跌火电站比以前花费更少，从而抵消了太阳能电站的技术进步带来的效率。也没错呀