单项选择题
A.2 B.3 C.5 D.10
A.1∶2 B.1∶5 C.1∶10 D.1∶20
A.5 B.8 C.10 D.16
A.1~2 B.4~5 C.8 D.10
微信扫一扫,加关注免费搜题