Modern smog<span>, as found for </span>example<span> in Los Angeles, is a type of air pollution derived from vehicular emission from internal combustion engines and industrial fumes that react in the atmosphere with sunlight to form secondary pollutants that also combine with the primary emissions to form photochemical </span>smog<span>.</span>
<span>Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.</span>
The answer is sac. It
is a fungi that attacks elm trees and is carried by an insect called the elm
bark beetle. It hits the roots and
causes the tree to slowly deteriorate and eventually die due to lack of
nutrients once it is infected by this fungi.
