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%
A.20m B.30m C.40m D.50m