user: You are a structured reasoning expert tasked with solving problems step by step. 
You first think about the reasoning process in the mind and then provide the answer. The reasoning process and answer should be enclosed within <think> </think> and <answer> </answer> tags, respectively, i.e., <think> reasoning process here </think> <answer> answer here </answer>. 
Given a question and the associated knowledge graph triplets (entity, relation, entity), you are asked to answer the question with these triplets and your own knowledge. 
You can break down the original question into several sub-questions and explore the given knowledge graph to solve them step-by-step. If there are multiple possible answers, choose one as the final answer. 
After thinking, when you finally reach a conclusion, clearly state the answer within <answer> </answer> tags, i.e., <answer> answer here </answer>. 
Question: When countries joined the location, that held the legislative session of the ,Seventh European Parliament? 
Knowledge Triplets: European Union, government.governmental_jurisdiction.government_positions, Member of the European Parliament
Legislature, rdf-schema#domain, Legislative session
Member of the European Parliament, government.government_office_or_title.governmental_body_if_any, European Parliament
Legislature, type.property.reverse_property, Sessions
Legislative session, type.type.expected_by, Sessions
Legislative session, type.type.properties, Date began
Seventh European Parliament, common.topic.notable_types, Legislative session
Legislative session, common.topic.article, m.03h92my
Legislative session, freebase.type_profile.kind, Definition
Jürgen Klute, government.politician.government_positions_held, m.010q_j69
European Union, government.governmental_jurisdiction.governing_officials, m.010q_j69
Legislative sessions, rdf-schema#range, Legislative session
Legislative sessions, type.property.reverse_property, Members
European Parliament, government.governmental_body.members, m.010q_j69
EP 2009 PIE, common.image.appears_in_topic_gallery, Seventh European Parliament
m.010q_j69, freebase.valuenotation.has_no_value, Appointed By (if Position is Appointed)
European Parliament, government.governmental_body.jurisdiction, European Union
EP 2009 PIE, common.image.size, m.029jd1k
m.010q_j69, government.government_position_held.office_holder, Jürgen Klute
Date ended, type.property.schema, Legislative session
Date ended, rdf-schema#domain, Legislative session
Germany, government.political_district.representatives, m.010q_j69
m.010q_j69, government.government_position_held.governmental_body, European Parliament
Member of the European Parliament, government.government_office_or_title.jurisdiction, European Union
Legislative session, type.type.expected_by, Legislative sessions
Legislative session, type.type.properties, Date ended
Legislature, type.property.schema, Legislative session
Legislative session, type.type.domain, Government
Legislative sessions, type.property.expected_type, Legislative session
m.010q_j69, government.government_position_held.district_represented, Germany
Date began, rdf-schema#domain, Legislative session
Seventh European Parliament, common.topic.image, EP 2009 PIE
m.010q_j69, government.government_position_held.jurisdiction_of_office, European Union
Legislative session, type.type.expected_by, Legislative Sessions
Legislative session, type.type.properties, Legislature
Member of the European Parliament, government.government_office_or_title.category, Member of Parliament
Legislature, owl#inverseOf, Sessions
m.010q_j69, government.government_position_held.legislative_sessions, Seventh European Parliament
Date began, type.property.schema, Legislative session
Legislative session, freebase.type_hints.included_types, Topic
Seventh European Parliament, common.topic.notable_for, g.1254_dzt4
m.010q_j69, government.government_position_held.basic_title, Member of Parliament
Member of Parliament, government.government_office_category.offices, Member of the European Parliament
European Union, organization.organization.founders, Germany
European Union, government.governmental_jurisdiction.government_bodies, European Parliament
Topic, freebase.type_profile.published, Published
Jürgen Klute, people.person.nationality, Germany
European Parliament, government.governmental_body.offices_positions, Member of the European Parliament
Member of the European Parliament, government.government_office_or_title.office_holders, m.010q_j69
Legislative sessions, owl#inverseOf, Members
Legislative session, freebase.type_profile.strict_included_types, Topic
Germany, organization.organization_founder.organizations_founded, European Union
m.010q_j69, government.government_position_held.office_position_or_title, Member of the European Parliament
Legislative session, freebase.type_profile.published, Published
Legislative session, type.type.properties, Members
Seventh European Parliament, government.legislative_session.members, m.010q_j69
Legislative session, type.type.expected_by, Session
Seventh European Parliament, common.topic.article, m.06zr1by

Answer: 1957-03-25
1973-01-01
1981-01-01
1986-01-01
1995-01-01
2004-05-01
2007-01-01
2013-07-01