Motocross bikers ride their bikes high over a dirt mount.
The biker threw there bikes at each other.
One does not ride and and threw their bikes at the same time.
exists e1 e2 x1 x2 x3 x4 x5.(Actor(e2,x1) & v_mount(e2) & r_high(e1) & over(e1,x5) & n_dirt(x5) & Theme(e1,x4) & Actor(e1,x3) & v_ride(e1) & n_bike(x4) & of(x4,x1) & n_thing(x1) & (x1 = x3) & n_biker(x1) & (x1 = x2) & ne_nam_motocross(x2))
exists e1 s1 x1 x2.(n_biker(x1) & all x3.(n_other(x3) -> at(e1,x3)) & a_there(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_throw(e1) & n_bike(x2))