What kind of vehicle is parked next to the fire truck by the road?
The vehicle is an ambulance.
    src        edge_attr  dst
0     0   to the left of   11
1     0  to the right of    7
2     0  to the right of    6
3     1   parked next to    7
4     1   to the left of    8
5     1  to the right of    5
6     1   to the left of    4
7     1               by    2
8     1   to the left of   11
9     1  to the right of    7
10    1  to the right of    6
11    4  to the right of   10
12    4  to the right of    1
13    4  to the right of    8
14    5   to the left of    7
15    5   to the left of    1
16    5             near    7
17    6   to the left of    1
18    6   to the left of    0
19    7   parked next to    1
20    7             near    5
21    7  to the right of    5
22    7   to the left of    1
23    7   to the left of    0
24    7               on    2
25    8  to the right of    1
26    8   to the left of    4
27   10   to the left of    4
28   11  to the right of    1
29   11  to the right of    0