Well, I haven't finished reading a book called Chemical Datang for a long time, but I have a good impression of Chinese style, which tells the story of a man who crossed back to the Tang Dynasty and made a fortune with his chemical knowledge. This is an extensive chemical industry. As far as I can see, his creation is limited to the improvement of rice, oil and salt. I wonder if there are any other big moves behind. I wonder if there has been any change in industry and commerce. (╯ _ ╰) ╭ As far as the first part is concerned.