1. None of the methods you mentioned will work. The font and roll surface are very important. If you use eraser, correction fluid, knife scraping, tape, or direct scratching, it will inevitably affect the roll surface. Neatness affects your score on the essay exam.

2. Let me tell you an authoritative solution: If you make a typo, don’t change the original typo. Just write the correct one after the original typo. For example: the word "Lun" in Yu Lun is written incorrectly due to a typo. Just write like this: Public ethics will suffice, and the marking teacher will understand. This method was suggested to me after I communicated with the provincial examination marking teacher, and I will share it with you now.