Two young people serve food.
Two people are serving food.
Two young people can just be two people.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_serve(e1) & n_food(x2) & n_people(x1) & a_young(s1) & Theme(s1,x1) & card_eq_2(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_serve(e1) & n_food(x2) & n_people(x1) & card_eq_2(x1))