A young man wears a helmet and protective clothing as he races his dirt bike through a muddy track.
A guy rides his dirt bike down a muddy pathway.
A dirt bike is usually ridden on a dirt road.  If the dirt road is wet, it turns into a muddy pathway.
(-x)
exists e1 s1 x1 x2 x3 x4.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & down(x2,x4) & n_pathway(x4) & a_muddy(s1) & Theme(s1,x4) & n_bike(x2) & of(x2,x3) & n_dirt(x3) & of(x2,x1) & n_male(x1) & n_guy(x1))