Which term refers to pro-slavery activists who crossed the kansas border to vote?

Border ruffians

Explanation:

Pro slavery activists who crossed the Kansas Border to vote were called Border Ruffians. They were activists from Missouri, a slave state, from 1854 to 1860 this border ruffians crossed the state border into Kansas Territorial grounds. Their mission was to force Kansas to accept slavery.

They caused violence and interfered in elections and attacked free state settlements. They were part of the cause of the American civil war.

which sentences ? that question is incomplete

answer; ///he could not explain why the continents drifted;