My diploma is not very good, and I am a bit of a Madahar, I do a lot of things, obviously I do it myself, I really forget, hehe, I am often told about this, so don't blame everyone......

I checked each chapter two or three times when it was posted, and there were many typos and sentences that didn't make sense, so I can only say sorry.

However, I will try not to make these mistakes and write carefully, so please rest assured.