A:what was the matter outside
B:what was matter outside
C:what the matter was outside
D:what is wrong outside
如图,在长方形ABCD中,AB=4cm,BC=5cm,在CD上取一点E,将△ADE折叠后点D恰好落在BC边上的点F,则CE的长为____ cm.
疾____
漆黑____
幸福____
消失____