The use of submarines on the high seas to sink any and all enemy ships of Germany
(
A. Unrestricted submarine warfare
O
B. internationally banded war tactic
C. totally inefficient use of war material
O
D. resulted in few deaths

They created so many things, were really and did not needed the European people.

The discovery process of the American continent represented for the Europeans the contact with a very peculiar mosaic of cultures. More than enchanted by the native's passive exoticism, Old World crews ran into complex civilizations. Many of these societies knew writing, developed mathematical systems, had extremely accurate calendars, and built larger urban centers than the cities of Spain.

Around the 7th century, the Andes Mountains were the scene of the development of the chimu, tiahuanaco and huari civilizations. Almost five hundred years later, the gathering of these peoples occupying the region would correspond to the vast Inca Empire, administered in the city of Cuzco. Prior to the arrival of the Spaniards, the Incas formed an expansionist state that reached regions from Ecuador to Chile and was home to about six million people.

In the central portion of the Americas, Olmecs, Toltecs, Teotihuacans, Aztecs, and Mayans formed distinct societies. The Maya, between the 3rd and 11th centuries, established a complex of autonomously functioning city-states through an efficient system of collective servitude. According to information, the Mayan civilization would have congregated more than two million inhabitants. When they arrived in America, the Spanish found most of these abandoned urban centers.