What was the purpose for city-states in ancient greece?

Briefly describe the roles/parts played by trumpet, clarinet, and trombone in new orleans-style collective improvisation, and explain why this type of collective improvisation is fundamentally different from what happens when a typical modern jazz group improvises together.

What was the midwest states often called because they were located in the center of the nation

Eter lives in a beautiful region. peter and other residents of his region use water from the river that flows through their region. recently, mark industries decided to set up their chemical plant near that river. peter realized that the waste from the chemical plant would pollute the river. he decided to seek a legal ordinance that would restrict the use of land near that river for specific use only. which type of zoning will peter and his region?