Answer to Question 1
Answer: Any two of these:
(i) ozone
(ii) particulates
(iii) carbon monoxide
(iv) sulfur dioxide
(v) nitrogen dioxide
Answer to Question 2
Answer: Any three of these:
(i) electric utilities
(ii) transportation
(iii) fuel combustion
(iv) industrial processes
(v) miscellaneous (dust, fires, etc)