A.3天,3天,5天 B.5天,5天,3天 C.5天,5天,10天 D.10天,10天,5天
A.6% B.20%LEL C.30%LEL D.40%LEL
A.600-700kPa B.700-800kPa C.800-900kPa D.900-1000kPa