Read the following materials: Material 1: "(Qi State) Taigong ... is to persuade female workers to weave ice dances and beautiful things and wear clothes to wear the world.

(1) silk. Cotton. Silk fabrics are too expensive and are often worn by the upper class, while cotton fabrics are soft, warm and durable, suitable for all walks of life.

(2) The third material is the farmer's household sideline, and the fourth material is the employment relationship in the silk industry in the middle and late Ming Dynasty. This shows that the progress of productive forces and the development of commodity economy have been greatly improved.

In the material problem composed of multiple pieces of material, each piece of material is often expounded from different angles, but it is generally around the same core problem, so we should pay attention to induction when browsing the material. Focusing on the development of silk industry, this topic aims to investigate the changes of raw materials and management methods in silk industry and the reasons for this change. Through the comparison between material one and material two, we can see that the textile raw material has changed from silk to cotton, and then summarize the reasons with the expression of material two. The contrast between material 3 and material 4 reflects the change of management mode from family sideline to employment relationship, which is the inevitable result of the development of productive forces.