本课配套习题挑战模式1/5

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单选题
难度系数:

1.

若mn>0,则 的值为( )


A:

1

B:

-1

C:

1或-1

D:

1或-3

  • 提示1PHA+55SxbW7vvJ4w77yM5Y+v55+lbe+8jG7lkIzlj7fvvIzmiYDku6XliIZt77yMbuWQjOS4uuato+WSjOWQjOS4uui0n+S4pOenjeaDheWGteWIhuWIq+iuqOiuujwvcD4=
  • 提示2PHA+be+8jG7lkIzkuLrmraPml7bvvIzljp/lvI89MSsxLTE9MTwvcD4=
  • 提示3PHA+be+8jG7lkIzkuLrotJ/ml7bvvIzljp/lvI89LTEtMS0xPS0zPC9wPg==