Which pair of actions best completes this graphic

In this unit, you read about transitions of power and the formation of newly independent nations in africa, asia, the americas, and the middle east. some of these transitions were peaceful, while others caused long-term instability. why do you think some countries were more successful than others with political transitions? what do you think were the biggest challenges facing newly independent countries? would it have been possible for leaders to prevent these problems before they happened? why or why not?

Describe the technology advancements that lead to explorers being able to sail great distances. [[ps: doesn't explain where. i am only speculating it's in europe.

Match these items. 1 . stephen douglas published "north star" 2 . frederick douglass first african slaves arrived in jamestown 3 . crittenden compromise proposed kansas-nebraska act 4 . republican party extend 36° 30' line to california 5 . abolitionists servitude in exchange for passage to the united states 6 . indentured struggle between proslavery and antislavery groups 7 . jefferson davis formed to prevent spread of slavery 8 . "bleeding kansas" wanted slavery abolished 9 . uncle tom's cabin president of confederacy 10 . 1619 harriet beecher stowe