单项选择题
A.0.1~1kg/m3 B.0.15~1.5kg/m3 C.0.2~2kg/m3 D.0.25~2.5kg/m3
A.1.5% B.2.4% C.3.4% D.4.5%
A.矿 B.焦 C.矿和焦 D.矿、焦和熔剂