15. What has been an effect of Tribalism (loyalty to one's tribe) in African nations such as Nigeria and Rwanda
a)all African states have united
c)civil wars and massacres
b)cooperation between tribes
d)rapid industrialization

. political or economical policy that isolates a country from participating in international relationships. it has been suggested that the united states participates in isolationism because of its lack of involvement in particular wars or alliances.

just finished this it is b. centrifugal force

not sure might be he acquired the entire oregon territory from great britain