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“xy>0”是“|x+y|=|x|+|y|”的( ) A.充分不必要条件 B.必...
“xy>0”是“|x+y|=|x|+|y|”的( )
A.充分不必要条件
B.必要不充分条件
C.充要条件
D.既不充分又不必要条件
考点分析:
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