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sponsorship (i.e. conducting under one's auspices); promotion; organizing; organising; hosting; staging
このイベントは市が主催しています。
This event is hosted by the city.
大学主催の講演会に参加してきた。
I attended a lecture hosted by the university.
主催者側の準備がすべて整いました。
All of the organizers' preparations are complete.