If you don't have writing skills, please tell me if you don't understand. If you don't tell me you don't know, how will I know that you don't know? If you say you don't know, I will know that you don't know. If you don't say you don't know, I don't have the ability to read minds, so of course I don't know. If you tell me that you don't know, I will tell you if you don't know. In fact, I don't know either.