单项选择题
A.0.4m B.0.6m C.0.8m D.1m
A.体积密度应不小于1.25g/cm3 B.体积密度应不小于1.5g/cm3 C.体积密度应不小于2.0g/cm3 D.体积密度应不小于2.30g/cm3
A.50%~90% B.50%~80% C.80%~90% D.80%~95%