单项选择题
A.1/4 B.1/5 C.1/6 D.1/3
A.10% B.20% C.30% D.40%
A.l/2至l/4 B.l/2至l/5 C.l/3至l/2 D.l/4至l/5
A.10 B.30 C.33 D.39
微信扫一扫,加关注免费搜题