单项选择题
A.6.25 B.2.56 C.5.62 D.6.90 E.7.00
A.0.6~0.9g B.0.9~1.2g C.1.2~1.5g D.1.5~1.8g E.1.8~2.0g
A.16% B.13% C.10% D.5% E.3%