A .When the fire involves paper products當火災(zāi)和紙制品有關(guān)時
B .When the fire is caused by flammable products當火災(zāi)由易燃物造成
C .When the fire involves electrical equipment當火災(zāi)和電器設(shè)備有關(guān)時
D .When the fire is in an enclosed area當火災(zāi)發(fā)生在一個封閉空間內(nèi)