A.1/100~3/100 B.1/1000~3/1000 C.3/1000~5/1000 D.7/1000~9/1000
A.2mm B.4mm C.6mm D.8mm
A.小于箍筋直徑的3倍 B.小于箍筋直徑的5倍 C.小于箍筋直徑的8倍 D.小于箍筋直徑的10倍