People crossing a city street.
People walk on the beach.
Beaches are right up on the water and not where you would find a city street to walk by.
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_cross(e1) & n_street(x3) & of(x3,x4) & n_city(x4) & (x1 = x2) & n_people(x1))
exists e1 x1 x2.(n_beach(x2) & on(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_people(x1))