[求助]OG11紫皮--46,53,70

实在想不明白了。。。

冰天雪地拜求解释！！！！！！！

46

Bank depositors in the United States are all financially protected against bank failure because the government insures all individuals’ bank deposits. An economist argues that this insurance is partly responsible for the high rate of bank failures, since it removes from depositors any financial incentive to find out whether the bank that holds their money is secure against failure. If depositors were more selective, then banks would need to be secure in order to compete for depositor’s money.

Which of the following , if true, most seriously weakens the economist’s argument?

A.      Before the government started to insure depositors against bank failure, there was a lower rate of bank failure than there is now.

B.      When the government did not insure deposits, frequent bank failures occured as a result of depositors’ fear of losing money in bank failures.

C.      Surveys show that a significant propotion of depositors are aware that their deposits are insured by the government.

D.     There is an upper limit on the amount of an individual’s deposit that the government will insure, but very few individuals’ deposits exceed this limit.

E.      The security of a bank against failure depends on the percentage of its assets that are loaned out and also on how much risk its loans involve.

答案是B.

53

There is a great deal of geographical variation in the frequency of many surgical procedures—up to tenfold variation per hundred thousand between different areas in the numbers of hysterectomies, prostatectomies, and tonsillectomies.

To support a conclusion that much of the variation is due to unnecessary surgical procedures, it would be most important to establish which of the following?

(A) A local board of review at each hospital examines the records of every operation to determine whether the surgical procedure was necessary.

(B) The variation is unrelated to factors (other than the surgical procedures themselves) that influence the incidence of diseases for which surgery might be considered.

(C) There are several categories of surgical procedure (other than hysterectomies, prostatectomies, and tonsillectomies) that are often performed unnecessarily.

(D) For certain surgical procedures, it is difficult to determine after the operation whether the procedures were necessary or whether alternative treatment would have succeeded.

(E) With respect to how often they are performed unnecessarily, hysterectomies, B
  prostatectomies, and tonsillectomies are representative of surgical procedures in general.
    

 选E怎么不对？答案是B

 选E怎么不对？答案是B

 70

When people evade income taxes by not declaring taxable income, a vicious cycle results. Tax evasion forces lawmakers to raise income tax rates, which causes the tax burden on nonevading taxpayers to become heavier. This, in turn, encourages even more taxpayers to evade income taxes by hiding taxable income.

The vicious cycle described above could not result unless which of the following were true?

(A) An increase in tax rates tends to function as an incentive for taxpayers to try to increase their pretax incomes.

(B) Some methods for detecting tax evaders, and thus recovering some tax revenue lost through evasion, bring in more than they cost, but their success rate varies from years to year.

(C) When lawmakers establish income tax rates in order to generate a certain level of revenue, they do not allow adequately for revenue that will be lost through evasion.

(D) No one who routinely hides some taxable income can be induced by a lowering of tax rates to stop hiding such income unless fines for evaders are raised at the same time.
            C

(E) Taxpayers do not differ from each other with respect to the rate of taxation that will cause them to evade taxes.
            

 选C，为什么不是E?