Two people in black leather ride motorcycles.
Two people are racing on their motorcycles.
The people might not necessarily be racing.
exists s1 x1 x2 x3 x4.(a_topic(x1) & in(x1,x2) & n_motorcycle(x2) & of(x2,x4) & n_ride(x4) & of(x2,x3) & n_leather(x3) & a_black(s1) & Theme(s1,x2) & n_people(x1) & card_eq_2(x1))
exists e1 x1 x2.(on(e1,x2) & n_motorcycle(x2) & of(x2,x1) & n_thing(x1) & Actor(e1,x1) & v_race(e1) & n_people(x1) & card_eq_2(x1))