Answer:
Wars, battles, draughts, and viruses.
Explanation:
In history many people faced tough wars and battles like the revolutionary war, world war, etc.
Draught has caused many people to die in history because of the lack of water they had, this most commonly occurred in desert areas.
Viruses like the Plague spread like a wildfire and were as deadly as a snake bite. This virus is the cause for many deaths in history.
The dynasties created gunpowder, porcelain, and paper currency which would benefit the economy. Politically, people were able to move around the empires, many cities gained a higher population, thus leading to a social advancement.
