What were the four main advantages of using African as slaves ?

Explanation:

Wakanda (/wəˈkændə, -ˈkɑːn-/) is a fictional country appearing in American comic books published by Marvel Comics.[2] It is located in sub-Saharan Africa, and is home to the superhero Black Panther.

Slavery has historically been widespread in Africa. Systems of servitude and slavery were common in parts of Africa in ancient times, as they were in much of the rest of the ancient world.[1] When the trans-Saharan slave trade, Indian Ocean slave trade and Atlantic slave trade (which started in the 16th century)[2] began, many of the pre-existing local African slave systems began supplying captives for slave markets outside Africa.[3][4]

The main slave routes in medieval Africa

A Zanj slave gang in Zanzibar (1889)

Slavery in historical Africa was practised in many different forms: Debt slavery, enslavement of war captives, military slavery, slavery for prostitution, and criminal slavery were all practised in various parts of Africa.[5] Slavery for domestic and court purposes was widespread throughout Africa.[6] Plantation slavery also occurred, primarily on the eastern coast of Africa and in parts of West Africa.[7] The importance of domestic plantation slavery increased during the 19th century, due to the abolition of the Atlantic slave trade.[8] Many African states dependent on the international slave trade reoriented their economies towards legitimate commerce worked by slave labor.

Explanation:

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a.that is my answer.

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c. troops marched forward in close formation against newer, more accurate weapons