✔ 最佳答案
Qin Shi Huang ruled with an iron fist. It was a case of follow his methods or face death. The main reason that he conquered all of China is that he overturned an unwritten rule that all prisoners of war there to be well treated. Qin Shi Huang on the other hand killed them.
It was all well that he introduced system of weights, writing and even the width of cartwheels but as a ruler he could. It was a case of do so or die.