a black dog wearing a red collar is dragging a rope though a river.
They are blowing up balloons
they refers to a group of people and cannot be a dog  one cannot blow a balloon while dragging a rope through a river
exists e1 e2 s1 s2 x1 x2 x3 x4 x5.(Theme(e2,x4) & Actor(e2,x1) & v_drag(e2) & though(x4,x5) & n_river(x5) & n_rope(x4) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_collar(x3) & a_red(s2) & Theme(s2,x3) & (x1 = x2) & n_dog(x1) & a_black(s1) & Theme(s1,x1))
exists e1 s1 x1 x2.(n_thing(x1) & a_up(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_blow(e1) & n_balloon(x2))