Three police officers on motorcycles on the street with pedestrians walking on the sidewalk in the background.
A group of police ride motorcycles next to people on the sidewalk.
A group of three officers  ride along the sidewalk.
exists e1 x1 x2 x3 x4 x5 x6 x7 x8.(n_background(x8) & n_sidewalk(x7) & n_street(x4) & a_topic(x1) & with(x1,x5) & in(e1,x8) & on(e1,x7) & Actor(e1,x6) & v_walk(e1) & (x5 = x6) & n_pedestrian(x5) & on(x1,x3) & on(x3,x4) & n_motorcycle(x3) & n_officer(x1) & of(x1,x2) & n_police(x2) & card_eq_3(x1))
exists e1 x1 x2 x3 x4 x5.(n_sidewalk(x5) & to(e1,x4) & on(x4,x5) & n_people(x4) & r_next(e1) & Actor(e1,x1) & v_motorcycle(e1) & of(x1,x2) & n_ride(x2) & of(x2,x3) & n_police(x3) & n_group(x1))