Space-Time Programmer: I Clicked on the Technology Tree in Ancient Times

The car accident threw him into an ancient battlefield littered with corpses, but he stuffed the entire modern knowledge base into his backpack. When the refugees used wooden spears to fight against the iron cavalry, Lin Jian silently lit gunpowder; when the plague engulfed the village, he distilled alcohol. In five years, he climbed from the pile of corpses to the position of national master, using science to reshape an era. When he opened his eyes again, he was back in the modern ward - only three days had passed. Today, the left hand is the killing and decisiveness tempered in ancient times, and the right hand is modern top academic knowledge. This time he wants to get back more than just the life he lost.