The Clean Air Act of 1963 was an improvement over the Air Pollution Control Act of 1955 because it _____.
provided twice as much money for the study of air pollution
set limits on emissions from factories
set limits on emissions from vehicles
prevented the deforestation of national parks
provided twice as much money for the study of air pollution
set limits on emissions from factories
set limits on emissions from vehicles
prevented the deforestation of national parks