Agriculture: 1. Hydro Mill (+10% agricultural production)

2. Livestock farming (agricultural yield +15%), aqueducts (agricultural yield +30%)

3. Windmills (+20% of agricultural output), steel farming tools (research required: steelmaking, +15% of agricultural output), large barns (20% reduction in famine incidence)

4. Regional transfer of water resources (need to study technology: canals, agricultural yield +50%, reduce the incidence of famine by 50%)

Industry: 1. Cast Iron Wheels (+5% Trade, +5% Army Movement Speed), Bow Pattern (5% reduction in construction time)

2. Large crane (10% shorter construction time)

3. Steelmaking (in the middle of the Middle Ages, it allows the production of late troops, and it is allowed to produce steel products), canals (+10% of trade)

4. Gears (+10% for industrial product production speed), gunpowder (+30% for mining production in the late Middle Ages, allowing research on gunpowder troops)

Business: 1 Chamber of Commerce (+5% of trade)

2. Smuggling Order (+5% of Valuable Resources Trade Revenue and Exports), Post Road (+5% of Trade Volume)

3 Tariffs (+10% for trade income, -1 for Minzhong)

Nautical: 1. Lighthouse (Fishery Harvest +10%)

2. Compass (+10% ship movement speed)

3 Xiyi Shipbuilding Law (+10% for all abilities of transport ships), Raid Order (can raid enemy waterways, ship raid income +5%)

Military: 1. Banner (+50% for team discipline, +5% for army recruitment)

2. Telescope (troop vision +1), War Horse Cultivation (cavalry unit level +1)

3. Warhawk (+2 unit vision, reduced chance of being ambushed)

4 Civilian-War System (-5% of the Army's Food Consumption, +1 Morale of the Militia-level Troops), National Army System (-10% of the Army's Recruitment Quota, +2% of the Maintenance Cost)

Literature: 1. Renaissance (popular +1)

2. Ideological enlightenment (you can study this after researching all medieval technologies, Christianity is transformed into Protestantism, and the industrial age technology tree is opened, and new troops can be recruited)

PS: This is still part of the information of the medieval tech tree, and the rest will be added slowly, and the research progress will be carried out in order.