This mainly depends on the impression of the teacher who changed the paper. Under normal circumstances, after the test paper is sealed, it can't be reopened until the marking place. If the teacher feels that the test paper is identical or plagiarized during the marking process, he has the right to report it to the superior for invalidation or deduction. When irrelevant words do not lead to cheating or bribery or attempt to make profits, points can not be deducted generally. This depends on what you write, and then on the teacher's mood. However, when the task of marking papers is heavy, this matter is laughed off.