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20 13 Jinyang Mathematics Senior High School Entrance Examination
Analysis: according to the open direction of quadratic function, the position of symmetry axis and the intersection of image and Y axis, the symbols of A, B and C are obtained, and then the options are obtained by special value method.

Solution: Solution: ∵ Parabolic opening downward, ∴ A < 0, ∴ 2A < 0,

When x= 1, a+b+c > 0, 2a+b > 0, 3a+2b+c > 0,

∴3a+c>-2b,∴-3a-c 0, c < 0 (the image intersects the y axis on the negative semi-axis),

∴ 3 | a |+| c | =-3a-c < 2b = 2 | b |, so option ④ is correct.

So the answer is: 134.