In what area of medicine did the incas make the most noteable advances?

What is the name for the main idea behind the settling of western lands by americans in the early-1800s?

Which statements explain reasons why unconformities occur? check all that apply. rocks along a fault break and move. igneous rock forms at earth’s surface. rocks erode and sediment is deposited. no sediment is deposited over a long time. igneous rock forms between sedimentary layers.

During the 1920’s why did the us policy change