2)E,偶想了好长时间,同意browse,The conclusion is 25 percent tax credit *** did little or nothing to stimulate the R&D spending by US business. E中是说tax credit 对business很少有效,等于没说。这里问的是一个specific case, 它回答一个broad possibility.
3)偶还是不明白OG关于A的解释:Since a tax credit generally improves business profits, if the conclusion is true choice A is unlikely to be true.,