A.50% B.60% C.70% D.80%
A.10% B.20% C.30% D.50%
A.含碳固體可燃物燃燒的火災 B.甲、乙、丙類液體燃燒的火災和可熔化的固體物質(zhì)燃燒的火災 C.帶電物體燃燒的火災 D.可燃氣體燃燒的火災