求助prep12的一道题

limin501

A proposed change to federal income tax laws would eliminate deductions from taxable income for donations a taxpayer has made to charitable and educational institutions. If this change were adopted, wealthy individuals would no longer be permitted such deductions. Therefore, many charitable and educational institutions would have to reduce services, and some would have to close their doors.
The argument above assumes which of the following?

A. Without the incentives offered by federal income tax laws, at least some wealthy individuals would not donate as much money to charitable and educational institutions as they otherwise would have.
B. Money contributed by individuals who make their donations because of provisions in the federal tax laws provides the only source of funding for many charitable and educational institutions.
C. The primary reason for not adopting the proposed change in the federal income tax laws cited above is to protect wealthy individuals from having to pay higher taxes.
D. Wealthy individuals who donate money to charitable and educational institutions are the only individuals who donate money to such institutions.
E. Income tax laws should be changed to make donations to charitable and educational institutions the only permissible deductions from taxable income.

这个题为什么我一直觉得d是对的呢。原文的意思是：富人因为税收的原因而不捐赠了，则福利机构就会收到严重影响而关门。中间少了一个条件，就是富人是主要捐赠者。D选项刚好能够说明这个assumption（如果取非，富人不是主要的捐赠者，则刚好能削弱文章结论）。A选项中，至少一些富人会捐的少了。但是at least some wealthy individuals 的比例并不确定啊，比如只是占了一小部分，那么就不影响到福利机构的结果呢。【到底是哪里理解的不对呢。。。】

brfmzbjz

Assumption 的题不等于加强的题
assumption 需要你取选项的否定意思，看是否削弱

A 是说 至少有一些人会因为税的减免取消，而减少捐赠
否命题是说，没有人因为税的减免取消，而减少捐赠
这就严重削弱了题目的结论

D 是说，wealthy individuals 是唯一捐赠的individuals,
否命题是说，wealthy individuals 不是唯一捐赠的individuals, 还有其他的来源；是不是唯一来源其实与donation减少没有关系，【比方说有的富人完全不在乎减免呢？】
再者，D说的是wealth individuals是individuals里的唯一捐钱的，那如果有其他的组织、机构、公司呢？

B 选项是同一个道理，捐钱的来源是否只有一个，不是本题逻辑的基础。基础应该是“到底减少税收减免，是否影响捐钱的意愿”，这一点很多人都在心里默认是一定的了，所以忽视了这个逻辑链中间的一环。

limin501

嗯，是因为我取非的问题，谢谢了