— is it from Suqian to Jiuzhai Valley?
—About l,900 kilometers away. But I'm not sure.
A:How often
B:How soon
C:How long
D:How far
如图,在等腰梯形ABCD中,BC∥AD,AD=5,DC=4,DE∥AB交BC于点E,且EC =3,则梯形ABCD的周长是( )