A.0.6mm/mB.1.2mm/mC.1.8m/mD.2.4m/m
A.30×1.1 B.35×1.2 C.45×1.3 D.55×1.4
A.不應(yīng)大于0.6mm/m B.不應(yīng)小于1.2mm/m C.應(yīng)等于1.2mm/m D.應(yīng)小于零