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We aim for a comprehensive development zone where industrial and commercial districts are fully integrated.
Literal
Industrial-district [and-と] commercial-district [subject-が] unified-body-became comprehensive [adjectival-な] development-zone [object-を] am-aiming-for [humble-ております].
Corporate/governmental communication in humble register. 一体となる ('become unified,' 'become one body') is a set phrase: 一 (one) + 体 (body) + となる ('become') = 'become a unified whole.' Common in institutional rhetoric about integration. 目指しております is the humble ~ております form (the humble version of ~ている), marking the action as the speaker/organization's own ongoing state while showing deference to the listener. This is standard in business communications and public-facing announcements from corporations, local governments, and organizations.