A:①④
B:②⑥
C:③⑤
D:①⑥
在平面直角坐标系中,点A的坐标为(0,3),点B和点D的坐标分别为(m,0),(n,4),且m>0,四边形ABCD是矩形.
The fire started on the second floor and it wasn't long ______ the whole building was burned down.