Question: What war in which one of the combatant countries was Poland, occurred while Woodrow Wilson was president?
Answer(s):
answer: World War I
answer: World War I

SPARQL query:
#MANUAL SPARQL
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT  ?x
WHERE
{ 
  {
    SELECT ?pfrom ?pto
    WHERE {
      ns:m.083q7 ns:government.politician.government_positions_held ?y0 .  # Woodrow Wilson  
      ?y0 ns:government.government_position_held.basic_title ns:m.060c4 ;  # President
          ns:government.government_position_held.from ?pfrom ;
          ns:government.government_position_held.to ?pto .
    }
  }
  {
    SELECT ?from ?to ?x
    WHERE {
      ?x ns:common.topic.notable_types ns:m.02h76fz . # Military Conflict
      ?x ns:time.event.start_date ?from . 
      ?x ns:time.event.end_date ?to . 
      ?x ns:military.military_conflict.combatants ?y .
      ?y ns:military.military_combatant_group.combatants ns:m.09c7w0 .  # United States of America
    }
  }
  FILTER (?to <= ?pto && ?from >= ?pfrom) ?x ns:military.military_conflict.commanders ?c .
?c ns:military.military_command.military_combatant ns:m.05qhw . 
}