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: tokyu corporation owns a what locomotive? 
Knowledge Triplets: Kamata Station, rail.railway_terminus.railways_terminating_here, Tōkyū Tamagawa Line
Tōkyū Tamagawa Line, rail.railway.terminuses, Tamagawa Station
Musashi-Nitta Station, metropolitan_transit.transit_stop.transit_lines, Tōkyū Tamagawa Line
Keita Gotō, base.schemastaging.context_name.pronunciation, g.125_m4dbg
m.010q2l9p, base.schemastaging.phone_sandbox.contact_category, Customer Service
m.0tw46lp, dataworld.gardening_hint.last_referenced_by, m.0h505wj
m.07fcnbx, rail.railway_operator_relationship.railway, Tōkyū Meguro Line
Tokyu Corporation, base.schemastaging.context_name.pronunciation, g.125_ks939
Kamata Station, metropolitan_transit.transit_stop.terminus_for_lines, Tōkyū Tamagawa Line
Keita Gotō, people.deceased_person.date_of_death, 1959
Tōkyū Tamagawa Line, rail.railway.terminuses, Kamata Station
m.010q2l9p, base.schemastaging.phone_open_times.tuesday_closing_time, T18
m.010q2l9p, base.schemastaging.phone_open_times.wednesday_closing_time, T18
m.019h, type.permission.controls, m.0h505wj
Tōkyū Tamagawa Line, rail.railway.opened, 2000-08-06
m.07fd6s2, rail.locomotive_ownership.locomotive, Tokyu 7000 series
Tokyu Corporation, business.employer.employees, m.0wfsfwd
m.07fc1h1, rail.railway_operator_relationship.railway, Tōkyū Den-en-toshi Line
m.0b6sg68, organization.organization_relationship.parent, Tokyu Corporation
m.010q2l9p, base.schemastaging.phone_open_times.thursday_open_time, T08
Tōkyū Ōimachi Line, rail.railway.operator_s, m.07fcstp
m.07fcdc0, rail.railway_gauge_relationship.railway, Tōkyū Tamagawa Line
Tokyu Corporation, rail.locomotive_owner.locomotives_owned, m.07fd6s2
Tokyu Corporation, organization.organization.date_founded, 1922-09-02
Unoki Station, metropolitan_transit.transit_stop.transit_lines, Tōkyū Tamagawa Line
Tokyu Corporation, organization.organization.founders, Keita Gotō
m.010q2l7w, internet.localized_uri.location, Japan
Tōkyū Tamagawa Line, metropolitan_transit.transit_line.stops, Numabe Station
m.010q2l9p, base.schemastaging.phone_open_times.saturday_open_time, T09:30
m.0wfsfwd, business.employment_tenure.company, Tokyu Corporation
m.07fcnbx, rail.railway_operator_relationship.operator, Tokyu Corporation
Numabe Station, metropolitan_transit.transit_stop.transit_lines, Tōkyū Tamagawa Line
Tokyu Corporation, rail.railway_operator.railways, m.07fcrs8
m.010q2l9p, base.schemastaging.phone_sandbox.caller_category, Consumer Service
Tokyu Corporation, organization.organization.child, m.0b6sg68
m.07fcstp, rail.railway_operator_relationship.operator, Tokyu Corporation
Tōkyū Tōyoko Line, rail.railway.operator_s, m.07fbvvd
m.010q2l9p, base.schemastaging.phone_sandbox.hearing_impaired, false
m.010q2l9p, base.schemastaging.phone_open_times.time_zone, Japan Time Zone
Keita Gotō, people.person.place_of_birth, Aoki
Tōkyū Tamagawa Line, metropolitan_transit.transit_line.transit_system, Tokyu Corporation
Tōkyū Tamagawa Line, metropolitan_transit.transit_line.stops, Kamata Station
Tōkyū Tamagawa Line, metropolitan_transit.transit_line.stops, Yaguchinowatashi Station
m.07fd6s2, rail.locomotive.owners, Tokyu 7000 series
Tōkyū Den-en-toshi Line, rail.railway.operator_s, m.07fc1h1
m.07fbvvd, rail.railway_operator_relationship.railway, Tōkyū Tōyoko Line
Tokyu Corporation, base.schemastaging.organization_extra.phone_number, m.010q2l9p
Keita Gotō, people.person.date_of_birth, 1882
Tōkyū Tamagawa Line, rail.railway.rolling_stock, m.07fcfxy
m.0h505wj, dataworld.gardening_hint.last_referenced_by, Tokyu Corporation
m.010q2l9p, base.schemastaging.phone_sandbox.service_location, Japan
m.0wfsfwd, business.employment_tenure.person, Hiroshi Okawa
Tōkyū Meguro Line, rail.railway.operator_s, m.07fcnbx
Kamata Station, metropolitan_transit.transit_stop.transit_lines, Tōkyū Tamagawa Line
Tokyu Corporation, base.schemastaging.organization_extra.contact_webpages, m.010q2l7w
m.010q2l9p, base.schemastaging.phone_open_times.sunday_closing_time, T17:30
Tōkyū Ikegami Line, rail.railway.operator_s, m.07fcrs8
Tokyu Corporation, rail.railway_operator.railways, m.07fbvvd
m.0wfsfwd, business.employment_tenure.from, 1942-12
Shimo-Maruko Station, metropolitan_transit.transit_stop.transit_lines, Tōkyū Tamagawa Line
m.010q2l9p, base.schemastaging.phone_open_times.monday_closing_time, T18:00
Tōkyū Tamagawa Line, metropolitan_transit.transit_line.stops, Unoki Station
g.125_ks939, base.schemastaging.pronunciation.yomigana, とうきょうきゅうこうでんてつ
Tamagawa Station, rail.railway_terminus.railways_terminating_here, Tōkyū Tamagawa Line
Tōkyū Tamagawa Line, rail.railway.type_of_railway, m.07fcdgy
m.07fcstp, rail.railway_operator_relationship.railway, Tōkyū Ōimachi Line
m.0b6sg68, organization.organization_relationship.child, Izukyū Corporation
m.010q2l9p, base.schemastaging.phone_open_times.friday_open_time, T08
Aoki, location.location.people_born_here, Keita Gotō
Hiroshi Okawa, people.person.employment_history, m.0wfsfwd
Tamagawa Station, metropolitan_transit.transit_stop.terminus_for_lines, Tōkyū Tamagawa Line
m.010q2l9p, base.schemastaging.phone_open_times.sunday_open_time, T09:30
m.07fcfr7, rail.railway_operator_relationship.operator, Tokyu Corporation
m.010q2l9p, base.schemastaging.phone_open_times.tuesday_open_time, T08
m.010q2l9p, base.schemastaging.phone_open_times.thursday_closing_time, T18
Izukyū Corporation, organization.organization.parent, m.0b6sg68
m.07fbvvd, rail.railway_operator_relationship.operator, Tokyu Corporation
Tōkyū Tamagawa Line, metropolitan_transit.transit_line.stops, Musashi-Nitta Station
m.07fcdgy, rail.railway_type_relationship.railway, Tōkyū Tamagawa Line
m.07fc1h1, rail.railway_operator_relationship.operator, Tokyu Corporation
Keita Gotō, people.person.gender, Male
m.0h505wj, type.object.permission, m.019h
m.010q2l9p, base.schemastaging.phone_sandbox.toll_free, false
Tōkyū Tamagawa Line, metropolitan_transit.transit_line.terminuses, Kamata Station
m.010q2l9p, base.schemastaging.phone_open_times.wednesday_open_time, T08
m.010q2l9p, base.schemastaging.phone_sandbox.country_code, 81
m.07fcrs8, rail.railway_operator_relationship.operator, Tokyu Corporation
m.0wfsfwd, business.employment_tenure.to, 1951
Tōkyū Tamagawa Line, rail.railway.length, 5.6
m.07fd6s2, rail.locomotive_ownership.owner, Tokyu Corporation
m.010q2l9p, base.schemastaging.phone_open_times.saturday_closing_time, T17:30
Tokyu Corporation, rail.railway_operator.railways, m.07fcnbx
Tamagawa Station, metropolitan_transit.transit_stop.transit_lines, Tōkyū Tamagawa Line
Tokyu Corporation, rail.railway_operator.railways, m.07fc1h1
m.010q2l7w, internet.localized_uri.language, Japanese
Yaguchinowatashi Station, metropolitan_transit.transit_stop.transit_lines, Tōkyū Tamagawa Line
m.07fcfxy, rail.rolling_stock_tenure.railway, Tōkyū Tamagawa Line
Keita Gotō, organization.organization_founder.organizations_founded, Tokyu Corporation
Izukyū Corporation, organization.organization.founders, Keita Gotō
Tokyu Corporation, metropolitan_transit.transit_system.transit_lines, Tōkyū Tamagawa Line
Tokyu Corporation, rail.railway_operator.railways, m.07fcfr7
m.07fcfr7, rail.railway_operator_relationship.railway, Tōkyū Tamagawa Line
m.010q2l9p, base.schemastaging.phone_sandbox.number, 03-3477-0109
Tokyu Corporation, rail.railway_operator.railways, m.07fcstp
Tōkyū Tamagawa Line, rail.railway.gauge, m.07fcdc0
Tōkyū Tamagawa Line, metropolitan_transit.transit_line.terminuses, Tamagawa Station
m.010q2l9p, base.schemastaging.phone_open_times.monday_open_time, T08
m.07fcrs8, rail.railway_operator_relationship.railway, Tōkyū Ikegami Line
Tōkyū Tamagawa Line, rail.railway.operator_s, m.07fcfr7
Tokyu 7000 series, rail.locomotive.owners, m.07fd6s2
Tōkyū Tamagawa Line, metropolitan_transit.transit_line.stops, Tamagawa Station
Keita Gotō, organization.organization_founder.organizations_founded, Izukyū Corporation
Tōkyū Tamagawa Line, metropolitan_transit.transit_line.stops, Shimo-Maruko Station
m.010q2l9p, base.schemastaging.phone_sandbox.service_language, Japanese Language
m.010q2l9p, base.schemastaging.phone_open_times.friday_closing_time, T18

Answer: Tokyu 7000 series