Which kind of animal is the wall behind of?
The wall is behind the cat.
    src        edge_attr  dst
0     0               of   11
1     1  to the right of    9
2     1               of   10
3     2               of   10
4     3           behind   10
5     4               of   10
6     5   to the left of    6
7     5               of   10
8     6               of   10
9     6            below    7
10    6  to the right of    5
11    7               on   10
12    7            above    6
13    8               of   10
14    9               of   10
15    9   to the left of    1
16   10          wearing    7
17   10      in front of    3
18   10               on   12
19   10            above   12
20   12            under   10