To decrease air pollution, a city began limiting the number of air-polluting
particles companies were able to release into the air. The companies
were required to use control devices that catch air-polluting particles.
The companies’ processes were also changed so that the lowest possible
amounts of polluting particles were released.
Tests show that these new city rules have not decreased the levels of acid
rain. Which activity is most likely the reason that implementing these
rules did not reduce acid rain levels?
M. The number of companies in the city has decreased.
P. The number of parks and green spaces in the city has increased.
R. The number of families moving into the city has decreased.
S. The number of automobiles and traffic jams has increased.