17.
如图,在△ABC中,点D是BC的中点,点E、F分别在线段AD及其延长线上,且DE=DF.下列条件使四边形BECF为菱形的是( )
0 282876 282884 282890 282894 282900 282902 282906 282912 282914 282920 282926 282930 282932 282936 282942 282944 282950 282954 282956 282960 282962 282966 282968 282970 282971 282972 282974 282975 282976 282978 282980 282984 282986 282990 282992 282996 283002 283004 283010 283014 283016 283020 283026 283032 283034 283040 283044 283046 283052 283056 283062 283070 366461
| A. | BE⊥CE | B. | BF∥CE | C. | BE=CF | D. | AB=AC |