OG-98 请教！

看不懂这题，oil burner和asphalt plants到底是什么关系？死活不明白……

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 adusted after two years to equal the actual cost savings.

Which of the following, if it occured, would constitute a disadvantage for Hotco of the plan described above?

A. Anther 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 burners is installed.

求解！多谢！

其实这个题是很容易的，asphalt是把oil加oil burner后产生出的一种产品，而题中说了hotco这家公司的产品就是oil burner,并说明了这种burner比其他burner都有效率，所以把它卖给了clifton asphalt公司，这是一家生产asphalt的公司。这些都是背景信息。然后题中的重点是clifton公司怎么样给hotco公司付这台burner的钱（过去两年clifton用原来的burner生产同样数量的asphalt说需要钱-clifton用了hotco的burner后生产同样数量的asphalt需要的钱）。

不知道这样说，你可不可以理解，不过这里这里要使这个推理陈立假设了一个条件就是在clifton公司用了hotco的burner以后oil的价格是变化不da的。

我想问D项

A decrease in the demand for asphalt

OG解释 D
            If demand decreases, less oil would need to be purchased, and Hotco would get more money.

需求小了，这个需求 是指C需要的burner 少了，还是指H对oil的需求少了