Questions 45--46 are based on the following：
Bank depositors in the United States are all financially protected against bank failure becausethe government insures all individuals’ bank deposits．An economist argues that this insurance ispartly 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 depositors’ money．
46．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 occurred as a
result of depositors’ fears of losing money in bank failures．
(C) Surveys show that a significant proportion 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。即“当政府不提供存款保障时，存款人对银行破产带来存款损失的恐惧是引起银行破产的原因。”
而题目说是“当政府提供存款保障时，提供存款保障是引起银行破产的原因。”
本题通过否定原有原因（提供存款保障），并引起他因（存款人的恐惧）进行削弱。
我的问题是两个原因是不是没有可比性：一个是“在政府不提供存款保障”的条件下（选项），一个是在“政府提供存款保障”的条件下（提干）。
我认为正确答案应该是“当政府提供存款保障时，存款人对银行破产带来存款损失的恐惧是引起银行破产的原因。”因为我认为正确选项中
当政府不提供存款保障时，存款人对银行破产带来存款损失的恐惧是引起银行破产的原因并不代表当政府提供存款保障时，其还是引起破产的原因。
感觉有点绕，但个人觉得锻炼逻辑挺有用，呵呵，盼回复 | 
