What aircraft is in front of the sky?
The aircraft is a jet.
   src        edge_attr  dst
0    2               in    3
1    2      in front of    3
2    2      in front of    6
3    3           behind    2
4    5  to the right of    6
5    6           behind    2
6    6   to the left of    5
7    6               in    3