A flight attendant showing passengers how to use the airplane safety vest.
 A flight attendant on duty.
Not all flight attendants on duty are showing passengers how to use the airplane safety vest.
exists e1 p1 s1 x1 x2 x3 x4 x5 x6 x7 x8.(n_vest(x6) & of(x6,x8) & n_safety(x8) & of(x6,x7) & n_airplane(x7) & a_topic(x1) & Topic(e1,p1) & exists e2.(Theme(e2,x6) & Actor(e2,x3) & v_use(e2)) & a_how(s1) & Manner(e1,s1) & Theme(e1,x5) & Actor(e1,x4) & v_show(e1) & n_passenger(x5) & (x1 = x4) & (x1 = x3) & n_attendant(x1) & of(x1,x2) & n_flight(x2))
exists x1 x2 x3.(a_topic(x1) & on(x1,x3) & n_duty(x3) & n_attendant(x1) & of(x1,x2) & n_flight(x2))