How much physical activity do children and teens need?

In which type of economy do the forces of supply and demand typically drive prices? a. a market economy b. a traditional economy a planned economy d. a command economy select the best answer from the choices provided. 0 0 em oo 0 0

Can someone me with this plz? ! i'm putting 20 points on it!

Explain why the rate of urbanisation is in the way it is between developed and undeveloped countries.