2. How many variables are tested in any controlled experiment?

What was the midwest states often called because they were located in the center of the nation

American s often refer to a country that is not the u. s as a a( domestic), or b(foreign)

The development of simple stone tools by early hominids led to the ability to procure meat more efficiently. this in turn led to the change in diet that included larger amounts of protein. many scholars believe that this shift in diet was a significant part of how our ancient ancestors adapted so quickly to a varied set of environments, and thus were able to begin cultural development. this demonstrates the intimate connection between