How have Europeans adapted the Danube River for their use? They use it for hydroelectricity.

They use it to prevent flooding.

They use it to build polders.

They use it for solar power.

Which process is a source of outdoor air pollution? check all that apply. burning gasoline at a refinery releasing fumes at a chemical plant emitting particles from a dump truck releasing radon gas from a generator emitting carbon monoxide from a heater