A psychological measure accurately measures what it's supposed to. what is this called?

Which of the following was a key accomplishment of the people of songhai? a. they had a strong military and became the largest empire in west africa. b. they established a center of islamic scholarship. c. they worked with iron and prospered from the gold-salt trade. d. they dominated in the trade of ivory, enslaved people, and animal skins.

The concept of limited government holds that

The platt amendment was a treaty that allowed the united states to build military bases in which country?