A.2;3 B.3;2 C.2;2 D.3;3
A.1孔,2m B.2孔,4m C.3孔,6m D.3孔,4m
A.<0.5%,≤0.5% B.≤0.5%,≤0.5% C.<0.5%,≤1% D.≤0.5%,≤1%