Answer to Question 1
High temperature and air pollution often appear at the same time and place. It is difficult to tell whether heat and air pollution act individually or collectively. The stationary domes of upper-level high pressure that can lead to heat waves also tend to produce multiple days of sunshine and stagnant air, conditions ideal for the formation of ground-level ozone and the accumulation of small particulates in the atmosphere. These, in turn, are directly linked to a variety of dangerous, potentially fatal health conditions, including cardiovascular and respiratory problems.
Answer to Question 2
C