Although many of the engagements of the American Revolution were conventional, guerrilla warfare was used to a certain extent during this conflict from 1775–1783, which made a significant impact. Guerrilla tactics were first used at the Battles of Lexington and Concord by the Patriots at April 19, 1775.
Many of the immigrants who cam to the US during this time quickly established communities, where they would replicate many of the customs of their homeland. A primary example of this would be food services and restaurants that still exist, especially in NYC.
In the year 1948 in Donora (Pennsylvania) smog killed 20 people and sickened about 7,000. The sulfuric acid, nitrogen dioxide and other toxic gases were caught in the thermal inversion and accumulated. It was one of the worst air pollution disasters in the history. Answer: C ) a thermal inversion and stagnant weather conditions.
