What is the vehicle in front of the hills that are green?
The vehicle is a train.
    src        edge_attr  dst
0     0   to the left of    7
1     0             near    6
2     0             near    4
3     0             near    7
4     0  to the right of    2
5     0  to the right of    6
6     0      in front of    8
7     0   to the left of    1
8     0           behind    9
9     1  to the right of    0
10    2   to the left of    0
11    2   to the left of   12
12    3   to the left of    9
13    3   to the left of    7
14    4             near    0
15    4          next to    0
16    5               of    0
17    5  to the right of   14
18    6             near    0
19    6   to the left of   14
20    6   to the left of   12
21    6   to the left of    0
22    7  to the right of    0
23    7  to the right of   12
24    7  to the right of   13
25    7  to the right of   10
26    7  to the right of    9
27    7  to the right of    3
28    7             near    0
29    7          next to    0
30    8   to the left of   12
31    8           behind    0
32    9               of    0
33    9   to the left of    7
34    9  to the right of    3
35   10   to the left of    7
36   11  to the right of   14
37   12  to the right of    8
38   12  to the right of    2
39   12  to the right of   14
40   12   to the left of    7
41   12  to the right of    6
42   13   to the left of    7
43   14  to the right of    6
44   14   to the left of    5
45   14   to the left of   12
46   14   to the left of   11
47   14           beside    0