采用圆钢弯制成脚手架时，双钩式圆钢直径不小于（)mm，单钩式圆钢直径不小于25mm，钢材不得有裂纹、锈蚀等缺陷，并应按规定检查钢钩质量。

A.21

B.23

C.25

D.27

A.8

B.10

C.16

D.25

A.10

B.16

C.18

D.20

A.圆钢直径不小于8mm

B.扁钢截面积不小于48mm²

C.扁钢截面积不小于28mm²

D.扁钢厚度不小于4mm

E.扁钢厚度不小于3mm

A.扁钢宽度的2倍

B.圆钢直径的6倍

C.圆钢直径的4倍

D.圆钢直径的2倍

A.28mm2

B.38mm2

C.45mm2

D.48mm2

A.Φ25mm

B.Φ26mm

C.Φ27mm

D.Φ28mm

A.2

B.6

C.4

D.8

A.Φ25mm

B.Φ26mm

C.Φ27mm

D.Φ28mm