单项选择题
A.120mm B.130mm C.150mm D.160mm
A.槽钢 B.等边角钢 C.H型钢 D.工字钢
A.直径48.3mm,厚度为3.6mm B.直径58.3mm,厚度为3.6mm C.直径48.3mm,厚度为4.6mm D.直径58.3mm,厚度为4.6mm