求助og 104 谢谢

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。

这句话怎么翻合适呢？为什么支持题目呢

题目大意：

1984年的R&D支出比1983年多了8％，但是增长速度却从1981年开始下降－1981年比1980年加快了16。4％。很明显，1981年国会制定的25％纳税抵扣政策（旨在提高研发费用支出）没有什么作用。

D，要是没有这个政策，1981年以后的研发支出不会低得这么厉害。

这里是虚拟，意思是确实1981年以后的研发费用比正常情况（即没有该政策）要低很多

即使没有这个政策，用于研发的支出也不会大幅度变低，意为：该政策没什么大效用。

我把这道题归类为加强或支持题。加强是加强结论。原文的结论是：议会1981年颁布的25%的税务信贷对刺激对科研的投入收效甚微。

A: 与business profits无关。

B: out of scope.

C: 有削弱结论的效果。

D: 如果没有1981年颁布的25%的税务信贷，1981年以来的科研投入也不会比实际情况更低。（意思就是：税务信贷没起作用）。正确答案。

thanks a lot

我也有点想不通了，虽然在做这题的时候选对了，但是看了答案以后又觉得E更像答案。

我觉得这题是归纳题，因为题干问的是。。。cannot be true unless,根据狒狒讲的，unless 相当于if not，也就是说，if not+正确选项，then the conclusion cannot true,其逆否命题，是if conclusion is true, then 正确选项，所以，此题应该为归纳，如果按照归纳作，那么D和E都挺像的，并且E直接说了tax credit 无效，不是比D说tax credit 反而降低了spending 要更好的归纳原文中的do little or nothing to stimulate such spending?

请高人指点！！！