have you ever heard a flight attendant warn airplane passengers to open the overhead bins carefully because the contents of the storage compartments may have shifted during the flight?
the motion of the airplane sometimes causes items in the overhead bins to change position abruptly.
shifting objects can be disorienting or even dangerous:
no one wants to hit on the head by an errant carry-on suitcase.
likewise, shifting of words and meanings in a sentence can be disorienting to the reader.
to avoid confusing your reader, be consistent with the nouns and pronouns you in your wirting.

어법상 틀린부분이 어디인가요.ㅜㅜㅜㅜㅜ
알맞게 고쳐적으래요.ㅜ