Li Yu thought to herself, It's engraving and printing! When she was in school, she learned about the development of printing. The teacher told them about the interesting experience of the North Song Dynasty's civilian inventor, Bi Sheng, who invented movable type printing. He even taught everyone to use glue to make movable type.
Seeing that Li Yu had fallen into deep thought, Zhou Jia stood up and said to Li Yu, "Yu'er, rest first. I'll go to the front yard to take a look."
Li Yu came out of her memories and said to Zhou Jia with a smile, "Xiao Xi, I remember that my master mentioned the method to print books. It's not as troublesome as you said. The method he mentioned is much simpler."
Zhou Jia looked at Li Yu in surprise. "Really? Tell me, how is it simple?"
Li Yu organized her words. "Xiao Xi, my master said that they used glue to make presses of the same specifications… After carving them, they burned them with fire…"
