A:had; for
B:made; for
C:had; by
D:made; by
运动系统由____、____和____组成.
如图所示,平行四边形ABCD中,E是BC边上一点,且BE=12EC,BD、AE相交于F点,
(1)求△BEF与△AFD的周长之比;
(2)若S△BEF=6cm2,求S△AFD.