Final answer:
Pre-civilizations used herbal remedies, bloodletting, and prayer and rituals to heal their sick.
Step-by-step explanation:
Pre-civilizations, such as Native Americans, used various methods to heal their sick. These methods included herbal remedies, bloodletting, and prayer and rituals. Herbal remedies involved using plants and natural substances to treat illnesses. Bloodletting, on the other hand, was a practice of removing blood from the body as a supposed treatment. Prayer and rituals were also commonly used as a way to seek healing through spiritual means.