单项选择题
A.10%~14%B.20%~25%C.30%~35%D.40%~50%E.60%~70%
A.0.6~0.8gB.1.0~1.2gC.1.3~1.4gD.1.5~2.0gE.2.2—2.5g
A.20%~30%B.16%~20%C.10%~16%D.16%~25%E.20%~25%