What is the relationship between market failure and free rider ?

Agerman mapmaker named a continent after me

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.

What did mrs zog say when mr zog said he was going mountain climbing in the himalayas answer key?