<span>Qin Shi Huangdi might I presume
</span>
1. gulf of tonkin incident
2. truman doctrine
3.containment of communism
probably a little off but it'll lead you in the right direction.
(I was literally learning this a couple months ago and my memory is a little rusty)
Of the options listed, the choice that describes a policy followed by the Freeman's Bureau is that it sought to A. educate former slaves. The Freeman's Bureau was developed in order to integrate freed slaves into American society by finding and pointing them towards housing, jobs, and education. However, it lasted for only a few years after Southern States regained a say in Congress and pushed for its defunding.
The most important reason for the collapse of Rome was the failure to actually integrate what they conquered. When Roman soldiers conquered new lands, it was rare that they ever attempted to force their culture, ideals, or laws upon the natives and barbarians. Thus, when the Empire began suffering internal struggles, the natives they had conquered decided to take action, which lead to the swift collapse by barbarian invasion from all sides. It's hard to pick a LEAST important reason, seeing that there were many of them, but I suppose a contender would most likely be the common refusal of the Empire to even acknowledge that barbarians were rising. On the outer edges of their territory, in places like Gaul and Morocco, the Roman government was reluctant to even recognize the threat of the barbarians, thinking that even accepting that these barbarians were causing trouble would weaken their prestige in the public eye.