首页->安全员c证
(A)开槽支撑、先撑后挖、分层开挖、严禁超挖
(B)开槽支撑、先挖后撑、分层开挖、严禁超挖
(C)开槽支撑、先撑后挖、整体开挖、严禁超挖
(D)开槽支撑、先挖后撑、整体开挖、严禁超挖