A combination of the words “smoke” and “fog,” smog is a kind of air pollution that plagues cities throughout the world. Smog can form in almost any climate but is worse during periods of warm, sunny weather, when it can build up to dangerous levels and cause a number of health problems. It has even led to acute incidents in which thousands of people in a single metropolitan area have been killed. In what city did the Great Smog of 1952 kill approximately 4,000 people over a four-day period? Discuss
Source: The Free Dictionary