question: Who was employed by a company that M4 , M5 , M6 , and M7 acquired and employed by M1 and M2
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
  ?x1 a ns:business.employer .
  ?x1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M4 .
  ?x1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M5 .
  ?x1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M6 .
  ?x1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M7
  }