Which inventions helped Chinese society during the Han dynasty?

During the Han dynasty, several key inventions significantly aided Chinese society. The development of paper around the 2nd century BCE improved communication and record-keeping, facilitating education and administration. The invention of the seismograph allowed for better understanding and response to earthquakes, enhancing public safety. Additionally, advancements in agricultural tools, such as the iron plow and the seed drill, boosted farming efficiency and food production.