Some of the trees on the side of the track are beginning to change color with the season.
The fall season is starting.
Sentence 1 is missing fall season is starting
exists e1 p1 x1 x2 x3 x4 x6.(n_season(x6) & n_track(x4) & n_side(x3) & n_tree(x2) & Topic(e1,p1) & Actor(e1,x1) & v_begin(e1) & exists e2 x5.(with(e2,x6) & Theme(e2,x5) & Actor(e2,x1) & v_change(e2) & n_color(x5)) & of(x1,x2) & on(x2,x3) & of(x3,x4) & n_thing(x1))
exists e1 x1 x2.(n_season(x1) & of(x1,x2) & n_fall(x2) & Actor(e1,x1) & v_start(e1))