A.14-30% B.15-30% C.16-30% D.18-30%
A.大于30% B.大于40% C.大于50% D.大于60%
A.動(dòng)力用煤、冶金用煤和化工用煤 B.動(dòng)力用煤、冶金用煤 C.動(dòng)力用煤和化工用煤 D.不能用于化工用煤