A borrowed answer fills the blank. It doesn’t fill your head.

A finished-looking page is not the same as a prepared head, and only one of them turns up with you on the day. A borrowed line sits on the paper without ever having been assembled by you, so there is nothing to retrieve later. Completion is easy to fake and capability is not.

Leave the blank where you genuinely cannot do it, with a note beside it saying what stopped you. A visible blank gets you help; a borrowed answer gets a tick and nothing else. Then go and close that particular gap.