封闭的带式输送机地面走廊内,带式输送机滚筒上方,甲烷传感器报警浓度、断电浓度、复电浓度分别是()、()、()
AA.≥0.5%CH4,≥0.5%CH4,
BB.≥1.5%CH4,≥1.5%CH4,
CC.≥1.0%CH4,≥1.0%CH4,
DD.≥1.5%CH4,≥2.0%CH4,
AA.≥0.5%CH4,≥0.5%CH4,
BB.≥1.5%CH4,≥1.5%CH4,
CC.≥1.0%CH4,≥1.0%CH4,
DD.≥1.5%CH4,≥2.0%CH4,