A.85% B.70% C.60% D.50%
A.碳酸鈣 B.碳酸鐵 C.碳酸鈣和碳酸鐵 D.重晶石
A.1.0~1.5g/cm3 B.1.5~2.0g/cm3 C.1.07~2.40g/cm3 D.1.07~2.80g/cm3