Who were mainly slaves in africa before any other cultures came to africa

African societies practiced human bondage long before the Atlantic slave ... The Portuguese had greater fear of a naval attack from other Europeans than ... Enslaved people lived in the dungeon for weeks or months until ships arrived to transport them to Europe or the Americas. ... American Indian culture of the Southwest.

a factory opens that mass-produces light bulbs.

explanation:

not sure if that's an answer to your questions but this is an example! : )