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15. Many experts regard the large increase in credit card borrowing in March not as a sign that households were pressed for cash and forced to borrow, rather a sign of confidence by households that they could safely handle new debt.
(A) rather a sign of confidence by households that they could safely
(B) yet as a sign of households’ confidence that it was safe for them to
(C) but a sign of confidence by households that they could safely
(D) but as a sign that households were confident they could safely
(E) but also as a sign that households were confident in their ability safely to
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(A)rather a sign of confidence by households that they could safely
【错误】 平行结构：不存在“not X rather Y”的平行结构。
(B)yet as a sign of households' confidence that it was safe for them to
【错误】 平行结构：“yet” (此处等同于“but”)两边连接的是“not as a sign that households were pressed for cash and forced to borrow”和“as a sign of households' confidence that it was safe for them to handle new debt”，语法功能上同为“as”引导的介词短语，但逻辑含义上，即语义上，没有(D)中“but”连接的“not as a sign that households were pressed for cash and forced to borrow”和“as a sign that households were confident they could safely handle new debt”两个“as a sign that……”结构更加平行，因此逊于(D)。
(C)but a sign of confidence by households that they could safely
【错误】 平行结构：“not as a sign that households were pressed for cash and forced to borrow”和“a sign of households' confidence that it was safe for them to handle new debt”，由于后者少了一个“as”，语法功能上无法使用“but”平行。
(D)but as a sign that households were confident they could safely
【正确】 “not as a sign that……”和“but as a sign that……”正确地用“but”平行在一起。
【大意】 很多专家并没有把三月信用卡借款的大幅增长看作家庭继续现金被迫借款的迹象，而是看作家庭有信息持有新的负债的迹象。
(E)but also as a sign that households were confident in their ability safely to
【错误】 平行结构： “but also”应和“not only”等连用，且“not only X but also Y”中，X与Y表达的是递进关系而非转折关系，意思上不合理。
【最优解题思路推荐】
根据平行结构的要求，发现只有(D)正确使用了“X but Y”的平行结构，因此选择(D)。