104. Spending on research and development by United States businesses for 1984 showed an increase of about
8 percent over the 1983 level. This increase actually continued a downward trend evident since 1981 – when
outlays for research and development increased 16.4 percent over 1980 spending. Clearly, the 25 percent tax
credit enacted by Congress in 1981, which was intended to promote spending on research and development,
did little or nothing to stimulate such spending.
The conclusion of the argument above cannot be true unless which of the following is true?
(A) Business spending on research and development is usually directly proportional to business profits.
(B) Business spending for research and development in 1985 could not increase by more than 8.3%
(C) Had the 1981 tax credit been set higher than 25%, business spending for research and development after 1981 would have increased more than it did.
(D) In the absence of the 25% tax credit, business spending for research and development after 1981 would not have been substantially lower than it was.
(E) Tax credits market for specific investments are rarely effective in inducing businesses to make those investments. 答案是D。以下是我推理过程，虽然推出来了，但我自己感觉疙疙瘩瘩的，不顺畅。请NN帮我看看其中有没有错的地方，谢谢！ 题干：花在R&D上的钱的增长率由逐年下降的趋势，显然tax的政策没能促进花费。 问：只有下面哪个对了，才能支持原文结论。 D：如果没有这个tax政策，1981年以后的花费就不会比现在更低，即花费会比现在高。现在有这个政策却低了，所以这个政策没用。 | 
