Who is riding on the surfboard?
The surfer is riding on the surfboard.
   src        edge_attr  dst
0    0               on    6
1    0       growing on    6
2    3             near    6
3    6          next to    3
4    6             near    3
5    7          wearing    1
6    7        riding on    5
7    7  looking down at    5
8    7               on    5