People sitting in a vehicle.
A couple is riding a bicycle built for two.
Riding a bicycle isn't sitting.
exists e1 x1 x2 x3.(a_topic(x1) & in(e1,x3) & n_vehicle(x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_people(x1))
exists e1 e2 x1 x2 x3 x4.(Theme(e2,x2) & Actor(e2,x1) & v_ride(e2) & for(e1,x4) & n_thing(x4) & card_eq_2(x4) & Theme(e1,x3) & v_build(e1) & (x2 = x3) & n_bicycle(x2) & n_couple(x1))