Question: Which state of Tendaho dam is the headquarters of Ethiopian People's revolutionary democratic Front located ?
SPARQL:
 SELECT DISTINCT ?uri WHERE { <http://dbpedia.org/resource/Ethiopian_People's_Revolutionary_Democratic_Front> <http://dbpedia.org/property/headquarters> ?uri. <http://dbpedia.org/resource/Tendaho_Dam> <http://dbpedia.org/property/country> ?uri}