How did the Qin dynasty lose power or why did the Qin dynasty decline?

Basically the very harsh authoritarian structure broke down when the emperor died. There was no decline; just poof! After fifteen years of very strict totalitarian rule.

Qin Dynasty (221–206 b.c.) Previously a minor state in the northwest, Qin had seized the territories of small states on its south and west borders by the mid-third century B.C., pursuing a harsh policy aimed at the consolidation and maintenance of power. Soon thereafter, Ying Zheng (259–210 B.C.), who would reunite China, came to the Qin throne as a boy of nine. He captured the remaining six of the "warring states," expanding his rule eastward and as far south as the Yangzi River, and proclaimed himself First Emperor of the Qin, or Qin Shihuangdi.

Qin, pronounced chin, is the source of the Western name China. Throughout his rule, Qin Shihuangdi continued to extend Chinese rule, eventually reaching as far south as Vietnam. His vast empire was divided into commanderies and prefectures administered jointly by civil and ... more.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.