What is the Columbian Exchange and what are some goods that were brought to the Americas? What are some goods that were brought to the Old World?

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite

Many somalian refugees sought entrance to the united states in 2006 and 2007. describe factors that encoura somalians to leave their country in the 1990s and 2000s

Aregion groups people together accodring to their traditions