A.工作面瓦斯爆炸 B.進(jìn)風(fēng)井筒火災(zāi) C.工作面火災(zāi) D.回風(fēng)井筒火災(zāi)
A.0.3 B.0.5 C.1.0 D.1.5
A.CH4≤1%,CO2≤1% B.CH4≤1%,CO2≤1.5% C.CH4≤1.5%,CO2≤1.5% D.CH4≤1.5%,CO2≤1%