Who is wearing boots?
The people are wearing boots.
    src        edge_attr  dst
0     1  to the right of    2
1     1   to the left of    7
2     1   to the left of   11
3     2   to the left of    7
4     2   to the left of    1
5     2   to the left of    4
6     2   to the left of   11
7     2   to the left of    9
8     4   to the left of    7
9     4  to the right of    2
10    4   to the left of   11
11    5               on   12
12    7  to the right of    1
13    7  to the right of    4
14    7  to the right of    2
15    9  to the right of    2
16    9           riding    5
17    9          wearing    8
18   11  to the right of    1
19   11  to the right of    4
20   11  to the right of    2