A.5min B.10min C.15min
A.地方標(biāo)準(zhǔn) A.國(guó)家標(biāo)準(zhǔn) C.行業(yè)標(biāo)準(zhǔn)
A.開(kāi)路流程 B.閉路流程 C.半開(kāi)路流程
A.20mm B.400mm C.15mm
A.10-15% B.15-50% C.20-70%