The backs of the heads of two men that are plugging their ears while riding the subway.
Two men are pluggling their ears on a subway.
Two men, who have the backs of their heads showing, are plugging their ears. They are riding the subway, therefore they are on it.
exists e1 e2 x1 x2 x3 x4 x5 x6.(n_subway(x6) & n_ear(x5) & of(x5,x2) & n_thing(x2) & n_head(x2) & n_back(x1) & a_topic(x1) & of(x1,x2) & of(x2,x3) & while(e1,e2) & Theme(e2,x6) & Actor(e2,x4) & v_ride(e2) & Theme(e1,x5) & Actor(e1,x4) & v_plug(e1) & (x3 = x4) & n_man(x3) & card_eq_2(x3))
exists e1 x1 x2 x3.(on(e1,x3) & n_subway(x3) & Theme(e1,x2) & Actor(e1,x1) & v_pluggle(e1) & n_ear(x2) & of(x2,x1) & n_thing(x1) & n_man(x1) & card_eq_2(x1))