the introduction of the _ _ brought an end to the Oregon Trail as the primary route for traveling west

Why have the aztec ruins in mexico city not been dug up?

There are 25 elements found in living things. how many of these elements are found in some organisms but not all? 1 , 6 , 19 , 25

In exchange for land, a knight agrees to be a sort of sub-vassal to a vassal. this agreement was known as: investiture homage tyranny subinfeudation