Which kingdom ruled in west africa up until the 19 century

the kingdom of mali
the kingdom of benin
the kingdom of ghana
the kingdom of songhai

An experimenter is examining the relationship between age and self-disclosure. a large sample of participants that are 25 to 35 years old and participants that are 65 to 75 years old are compared, and significant differences are found with younger participants disclosing much more than older people. the researcher reports an effect size of .34. what does this mean

What is it called when countries build lots of weapons to store and them in case of a war?

When and why were fingerprints first used in the united states