Air quality in Boston is generally very good: during the ten-year period 2004–2013, there were only 4 days in which the air was unhealthy for the general public, according to the EPA. COUNT 3
QSN1 How is the air quality in Boston? ANS1 generally very good QSN2 How many days between 2004 and 2013 was the air unhealthy? ANS2 4 days QSN3 Who determined that the air quality was unhealthy on those 4 days? ANS3 the EPA