A.20%~30% B.30%~50% C.50%~70% D.70%~80%
A.絕對(duì)標(biāo)高 B.相對(duì)標(biāo)高 C.建筑標(biāo)高 D.結(jié)構(gòu)標(biāo)高
A.不燃性,1h B.不燃性,0.5h C.難燃性,1h D.難燃性,0.5h