A:-6
B:-12
C:-6与-12
D:任何数
① x2x−1−x−1
② x+2x2−2x−x−1a2−4x+4
③ (xy−x2)(1x+1y−x)
④ (x﹣1﹣ 8x+1 )÷ x+3x+1 .
每只小猫分____条鱼.