happen / occur

一体化: unification; integration

一体化: to unify, to integrate

一体: on earth, the heck, in the world / 一帯: whole (place), all over

what on earth / in the world / the heck / the hell / on earth / the devil / the fuck / in the hell / the fuck / indeed

(adverbial particle, dismissive, derogatory) emphasizes disgust, contempt, or otherwise negative feelings of the speaker: whatever

on earth, the heck, in the world (used for emphasis and to express incredulity)

unification; integration

to unify; to integrate

region, zone