How did shi huangdi rule and control his empire

He established reforms in many areas including: Government - Emperor Qin did not want the conquered states to think of themselves as independent nations. He divided the country into administrative units. There were 36 "commanderies" which were further divided into districts and counties.

Explanation:

what the first or next guys says

the correct answer is:   the domino theory states that if one country in a region came under the influence of communism, then the surrounding countries would follow in a domino effect.