Question

Please Help me I really need help

Which of these was an accomplishment of the Han Dynasty?
the invention of the seismograph

finding a water passage to Europe

the invention of the ballpoint pen

the invention of the abacus

Answer 1

The first (if you can say it that way) seismograph was invented by the scientist and astronomer Zhang Heng, a fact that took place during the regency of the Eastern Han dynasty.