Final answer:
Gathering-hunting is the key to successful subsistence for hunter-gatherers. They rely on gathering fruits, nuts, and berries, as well as hunting wild animals for food.
Step-by-step explanation:
Gathering-hunting is the key to successful subsistence for hunter-gatherers. In this subsistence strategy, people rely on the natural resources available in their environment. They gather fruits, nuts, berries, and roots, and they hunt and trap wild animals. Gathering is actually the main source of calories for such groups, providing the majority of their food.