Who is on the skateboard that is made of wood?
The boy is on the skateboard.
     src        edge_attr  dst
0      0        riding on   31
1      0          wearing   26
2      0           behind    1
3      0   to the left of    7
4      0               on   31
..   ...              ...  ...
121   30  to the right of   23
122   31               on    9
123   32  to the right of   21
124   32  to the right of    0
125   32               on    9

[126 rows x 3 columns]