231.FISCO焊接裂纹试验需依次焊接4条长为( )的试验焊缝,焊接间距为10mm

231.FISCO焊接裂纹试验需依次焊接4条长为( )的试验焊缝,焊接间距为10mm

A.lOmm

B.20mm

C.30mm

D.40mm

正确答案是D