单项选择题
1/10,2/15,1/6,1/5,()A.7/30B.1/7C.1/3D.1/30
单项选择题1/10,2/15,1/6,1/5,()
A.7/30 B.1/7 C.1/3 D.1/30
-1,1,3,5,( )A.6B.8C.7D.-8
单项选择题-1,1,3,5,( )