What is the ground covered by?
The ground is covered by the grass.
     src        edge_attr  dst
0      0               in   23
1      0  to the right of    1
2      0  to the right of   34
3      1           behind   34
4      1   to the left of    7
..   ...              ...  ...
167   35   to the left of    1
168   35  to the right of    3
169   35   to the left of   34
170   35   to the left of   31
171   35  to the right of   32

[172 rows x 3 columns]