Hotco oil burners, designed to be used in asphalt plants, are so efficient that Hotco will sell one to the Clifton Asphalt plant for no payment other than the cost savings between the total amount the asphalt plant actually paid for oil using its former burner during the last two years and the total amount it will pay for oil using the Hotco burner during the next two years. On installation, the plant will make an estimated payment, which will be adjusted after two years to equal the actual cost savings.
Which of the following, if it occurred, would constitute a disadvantage for Hotco of the plan described above?
(A) Another manufacturer’s introduction to the market of a similarly efficient burner
(B) The Clifton Asphalt plant’s need for more than one new burner
(C) Very poor efficiency in the Clifton Asphalt plant’s old burner
(D) A decrease in the demand for asphalt
(E) A steady increase in the price of oil beginning soon after the new burner is installed

这题的答案是E,不太明白.因为题目说
new burner的价钱=今后两年使用新burner后的燃油费用-前两年内使用旧burner时的燃油费用
如果油价涨了,不正好是被减数大了么?
请大家帮忙,先谢谢~~~

the plant will make an estimated payment, which will be adjusted

after two years to equal the actual cost savings

You may miss the above sentence. The cost saving paid for New

burner manufacturer is estimated. As a result, if the price of oil

keep increasing after installation, the above estimation will be

lower than the actual price difference.

To be discussed.........

原文意思如下: 这个冬冬的钱=A两年内(last two year, 是个定值)用老burner的油钱(假设10毛钱)-B两年内(next two year,是个变动值)用新burner的油钱

如果油价不变,A不变,B(假设5毛), 则冬冬=5,

如果油价高了,则A还是不变,B变7毛,则冬冬=3

如果油价低了,则...............,B变3毛了,那么厂家就发了

这道题我的理解是，new burner的价钱=前两年内使用旧burner时的燃油费用-今后两年使用新burner后的燃油费用，所以OIL价格涨了，HOTCO就亏了。而你说“new burner的价钱=今后两年使用新burner后的燃油费用-前两年内使用旧burner时的燃油费用”，正好把被减数和减数搞反了。