Final answer:
The third early civilization developed along a 30-mile stretch of the central coast of South America. Early civilizations in South America emerged along the coast due to geographic factors such as the high Andes mountains and the inhospitable Amazon Basin.
Step-by-step explanation:
The third early civilization developed along a 30-mile stretch of the central coast of South America. Early civilizations in South America, such as the Norte Chico civilization, emerged along the coast due to the geography of the continent. The high Andes mountains and the inhospitable Amazon Basin made the interior of the continent less favorable for settlement, driving civilizations to develop along the coast.