prep08-82

yaoyuanyuan

Technologicalimprovements and reduced equipment costs have made converting solar energydirectly into electricity far more cost-efficient in the last decade.  However, the threshold of economic viabilityfor solar power (that is, the 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) is unchanged at thirty-five dollars.

Whichof the following, if true, does most to help explain why the increasedcost-efficiency of solar power has not decreased its threshold of economicviability?

A.The cost of oil has fallen dramatically.
B.The reduction in the cost of solar-power equipment has occurred despiteincreased 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 worthexploiting become economically viable.


答案c，题干括号内的内容有点不理解，求高人指教

annieview

不晓得能看懂不。有可能有漏洞，大题思路应该是这样。

annieview

解决矛盾题
DISCREPANCY: S-P的cost-ef 上升，但是S-P的viability threshold不变
这里的关键理解处在于viability，而stimuli中也特意括号中解释了，（
oil的price would have to rise使得SP更加经济），也就是说，如果按
照常理说：油价上升，sp的viability应该上升。
这样的话逻辑链就很顺了。如以下：
                                           SOLAR POWER           
   OIL
cost-Ef                                    上升                  
          不晓得-----》应该是上升了
price                                        较低               
            更高
VIABILITY(考虑以上两因素)     不变 （unchanged）  不变