What skills were needed for human species to populate the earth?

The basic rule for survival is to protect oneself in the wilderness. Then comes the provide that is food for a living, and at last to produce offspring for the future generation. The evolution of the early human started when they became bipedalism, lived in caves and was engaged in hunting and gathering later they invented the fire and engaged themselves in farming and living in groups in one place.

the answer is expolration. hope this !

i believe the correct answer is option b. most eastern european nations joined nato.

though i could be wrong, option d. the eastern european nations were granted complete independence, would be another choice.

hope this ! : )