Why did early civilizations begin in river valleys? A. the flooding or rivers created good farmland.

B. rivers provided plenty of fresh water.

C. people could hide from enemies in river valleys.

D. river valley had many trees for building.

Match each idea to the correct principle of government. federalism separation of powers checks and balances divides the powers of government into different branches arrowright divides the powers of government between central and state governments arrowright each branch of government has certain powers that prevents the abuse of power on the people arrowright