A.三級,0.2mm B.三級,0.3mm C.三級,0.4mm D.二級,0.2mm
A.受彎構件及受扭構件 B.軸心受壓構件及偏心受壓構件 C.軸心受拉構件及偏心受拉構件 D.軸心受拉構件及小偏心受拉構件
A.≥d且≥25mm B.≥1.5d且≥30mm C.≥d且≥30mm D.≥1.5d且≥25mm