question: What actor of M1 , M2 , and M3 did M0 employ
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 ns:film.actor.film/ns:film.performance.character M1 .
  ?x0 ns:film.actor.film/ns:film.performance.character M2 .
  ?x0 ns:film.actor.film/ns:film.performance.character M3 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M0
  }