单项选择题
25 15 10 5 5 ( )A.10B.5C.0D.-5
单项选择题25 15 10 5 5 ( )
4/3,7/6,10/9,13/12,( )A.13/14B.14/15C.16/15D.17/16
单项选择题4/3,7/6,10/9,13/12,( )
105,206,307,408,( )A.704B.509C.603D.506
单项选择题105,206,307,408,( )