question: What was acquired by M0 , acquired by a company , and acquired by M1 , M2 , M3 , and M4
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company ?x1 .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M0 .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M1 .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M2 .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M3 .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M4 .
  ?x1 a ns:business.employer
  }