Making Military Hardware, Starting with Bright Sword

Do you want to know what we, Mr. Li, did before the plot of Liangjian unfolded? I want to know what we, Lao Li, can do after the Eighth Route Army has enough good weapons in their hands. Really want to know? Then read a book! After reading it, you will understand the persistence and hardships of the Eighth Route Army members at that time! Even if the protagonist has a system...