单项选择题
A.4m B.5m C.6m D.7m
A.15mm B.20mm C.25mm D.30mm
A.承重 B.阻断 C.通风 D.采光
A.Ⅰ~Ⅳ级 B.Ⅰ~Ⅴ级 C.Ⅱ~Ⅳ级 D.Ⅱ~Ⅴ级
A.2MB.3MC.4MD.5M
A.楼梯 B.自动扶梯 C.爬梯 D.楼板
A.40~70mm B.50~80mm C.60~90mm D.70~100mm
A.5mm B.10mm C.15mm D.20mm
A.115mm B.178mm C.240mm D.365mm
A.60kPaB.70kPaC.80kPaD.90kPa
A.24m B.26m C.28m D.32m