若不等式(a-2)x2+2(a-2)x-4<0对一切x∈R恒成立,则a的取值范围是


  1. A.
    (-∞,2]
  2. B.
    [-2,2]
  3. C.
    (-2,2]
  4. D.
    (-∞,-2)
C
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