While on vacation, a student found a kind of rock he had never seen before. The rock was grey, but when he looked closer, the student saw white and black flecks in it.
Is this rock a pure substance, a mechanical mixture, or a solution? Explain your answer.

How has the elimination of trade barriers affected the movement of goods among member countries of the european union? a. member countries are able to produce all the goods they need. b. goods can move freely among member countries. c. member countries no longer need to trade with countries outside the eu. d. larger countries are able to import more goods than smaller ones.

What does the point on the graph represent? a. aggregate supply and demand equilibrium b. aggregate supply c. aggregate rising prices and supply d. aggregate rise in gdp

Adolescents can display egocentrism when they become about changes in their lives.