Question

What was the largest single source of air pollution around the world by the 1990s?

a. meta smelting,
b. waste incineration,
c. auto emissions,
d. chemical emissions

Answer 1

The correct answer for the question that is being presented above is this one: "c. auto emissions." The largest single source of air pollution around the world by the 1990s is cause by auto emissions. There are many cars run around the streets everyday.