Why was the qin dynasty so short-lived?

it was short because there was only one ruler and he drank and put mercury all over himself because he wanted to find something that would hav him live forever, and he heard mercury would help. so instead of living longer, he was kiling himself slowly

answer; people where able to travel across the u.s.a faster than any other mode of transportation,travel time was about a week,from coast to coast

b. sec, foreign relations