Dirt bikers traverse a series of jumps.
some dirt bikers are falling off their bike
Just because Dirt bikers traverse a series of jumps does not mean they are falling off.
exists e1 x1 x2 x3 x4.(Theme(e1,x3) & Actor(e1,x1) & v_traverse(e1) & of(x3,x4) & n_jump(x4) & n_series(x3) & n_biker(x1) & (x1 = x2) & ne_nam_dirt(x2))
exists e1 s1 x1 x2 x3.(a_off(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x1) & v_fall(e1) & n_bike(x3) & of(x3,x1) & n_thing(x1) & n_biker(x1) & of(x1,x2) & n_dirt(x2))