单项选择题
8/9,-2/3,1/2,-3/8,9/32,( )A.-27/128B.25/128C.3/64D.5/6...
单项选择题8/9,-2/3,1/2,-3/8,9/32,( )
3,-6,9,-12,15,( )A.18B.-15C.21D.-18
单项选择题3,-6,9,-12,15,( )