og-104

lll123

1. spending on reseach 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 reseach and development increased 164 percent over 1980 spending. clealy the 25percent tax credit enacted by congress in 1981,which was intended to promote spending on research and development, didi little or nothing to stimulate such spending.
    the conclusion of the argument above cannot be true unless which of the following is true?

the answer is "in the absence of the 25percent tax credit, business spending for research and development after 1981 would not have been substantially lower than it was."  

i understand 'without tax credit, business spending for research and development after 1981 would have been substantially lower than it was.'
可我决觉得答案和刚好和它解释的逻辑相反？

linlin315

不矛盾吧
答案的逆否命题不就是再说 substantially lower --->25% tax credit,不就是tax是下降的原因嘛
所以才能得出文中的结论，就是tax根本就没起到促进的作用啊！！对不

toto2004

斑竹解说的只是d,还没看明白d和对应的解释的关系。费心再指点一下,谢谢！

william_T

题目说1981年开始征的税，本来是要促进spending的，但是没效果。

答案说：如果没有征税，那么1981年以后的spending不会比征了税以后的spending低多少。

这正说明了有没有征税结果都差不多，即题干中说的 tax credit did little or nothing to stimulate such spending。

xixi2004

'without tax credit, business spending for research and development after 1981 would have been substantially lower than it was.'
这句是对d地解释，“如果没有征税，81年后的spending会比征税后低很多？这是怎么回事？og解释有问题吗？

思谦

The conclusion that the tax credit did nothing to stimulate spending on research and development would not be true if, without the credit, such spending would have been even lower than it actually was. Thus choice D must be true for the conclusion to be true and is the best answer.

请5楼的看涂了颜色的部分

captain_ma

对的，d是说有没有它都无所谓（tax credit),so d supports the conclusion!