What three animals did eropeans introduce to north america?

What was the first civilization name of the indians?

The system of checks and balances was designed for what purpose? fear of strong state power to keep power out of one branch to appease the southern states to allow the judicial branch to have equal power

Why did poland, hungary, and east germany join the warsaw pact? a)their people voted to join in free elections. b)their efforts to join nato failed. c)they wanted to stop the spread of communism in europe. d)they were soviet satellites that had little choice.