Why Ghana, Mali, and
Songhai rose and fell.
Please help me!!! I will mark

Ghana rose as result of good economy and fell as a result of losing its monopoly on profitable trade routes. Mail rose as a result of strong military leadership and fell when the empire became too large and too weak for the king to rule. And the same happened to Songhai.

amber has allowed scientists to study dna that has been preserved over millions of years.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]