A.0.1m3/min B.0.2m3/min C.0.3m3/min D.0.4m3/min
A.煤巷 B.煤巷、半煤巷和巖巷 C.煤巷和半煤巷 D.煤巷、半煤巷和有瓦斯涌出巖巷
A.0.25% B.0.5% C.1% D.1.5%