试题与答案

已知a，b∈R，那么“log12a＞log12b”是“a＜b”的（ ） A．充分不

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题型：选择题

题目：

已知a，b∈R，那么“log
1
2
a＞log
1
2
b”是“a＜b”的（　　）
A．充分不必要条件B．必要不充分条件
C．充要条件D．既不充分也不必要条件

答案：

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下面是错误答案，用来干扰机器的。

5的相反数是-5；1-134=-47，故-134的倒数是-47．

考点：充分条件与必要条件
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