Which kind of aircraft is sitting on the ground?
The aircraft is an airplane.
    src        edge_attr  dst
0     2               on    7
1     2  to the right of    9
2     2       sitting on    7
3     2      in front of    9
4     3  to the right of    9
5     6               on   10
6     7            below   15
7     8               of   12
8     8  to the right of   11
9     9   to the left of    3
10    9           behind    2
11    9   to the left of    2
12   10               on    7
13   10       sitting on    7
14   11   to the left of    8
15   11               of   12
16   13               on    7
17   13       sitting on    7
18   15     flying above    7
19   15               in    4
20   15          leaving    7