Which of the following is a secondary air pollutant?
A) chlorofluorocarbons
B) carbon monoxide
C) ozone
D) sulfur dioxide
E) mercury
Question 2
According to the greenhouse gas emissions data collected by Duke University, the year that Duke's rate of emissions increased the most dramatically was ________.
A) 2006-2007 B) 1990-1991 C) 1995-1996 D) 2009-2010 E) 1999-2000