找规律填数。(1)2,5,8,2,5,8,2,5,( ),( );(2)35,30,25,20,15,( ),( ),( );(3)6,8,10,12,14,16,( ),( );(4)1,4,7,10,13,16,( ),( );(5)9,19,29,39,49,( ),( )。