Why did the Spanish Empire rely on the native population to mine silver?

i think the answer is c, rivers.

explanation:

sometimes, borders fall along natural boundaries like rivers or mountain ranges. for example, the boundary between france and spain follows the crest of the pyrenees mountains. for part of its length, the boundary between the united states and mexico follows a river called the rio grande. the borders of four countries divide africa’s lake chad: niger, chad, cameroon, and nigeria.

i don't understand.. what's the question you're asking here? ?

the new england colonies tried to the native americans and also, known as the north-eastern, included massachusetts colony, rhode island colony, connecticut colony, and new hampshire colony. the region was first found by people from britain in 1620.

these colonies provided fish, whale products, and  lumber. they imported agricultural products from other regions.

the  geology of new england  includes many mountains, and it is thick with trees and rivers. the forest provided, large amount of lumber for new england and led them to specialize in the  shipbuilding  industry. however,the landscape was unsuitable for cereal crops, so they were imported from the other colonies.[1]originally this region had fertile soil, but during the  last glacial period, large glaciers scraped away the fertile soil and moved it south, leaving a rocky landscape that was not suitable for farming

economic advantages.

first of all, the south suffered a lot more damage then the north.

second of all, because the south has better weather, they usually stuck to farming instead of building up industries. the north, on the other hand, built up their industries much quicker and had a lot more factories then the south. also, more people lived in the north then in the south, allowing the north to quickly build up their armies. 

hope this