を中心に => focused on; centered on~ N2
一緒に => together N5
を契機に => as a good opportunity/chance to N2
Expected
一度に => all at once N3
を[機「き」]に => Use A as an opportunity N1
Time, Situation
一通り => Basically, (get) over, done N2
Base, base
[中心「ちゅうしん」]に => With A as the center N2
Miscellaneous
一方だ => more and more; continue to ~ N2
一応 => more or less; pretty much; roughly; tentatively ~ N2
一体 => …the heck; …in the world; …on earth N3
を[契機「けいき」] => As a good opportunity A, (do) B N2
Information, Report
一方 => on one hand, on the other hand; although ~ (conjunction) N2