In the United States the average life expectancy in the first paragraph is 78 years. This number has increased over the years. The second paragraph should be: "There are a number of factors that influence how long someone lives. Lifestyle choices such as quitting smoking or eating healthily can have a significant impact. The third paragraph should be: "Genetics also play an important role in how long someone lives. If a person's family has a history of heart disease they are more likely to get this condition.