Question

measurement of several of the air pollutants by the epa includes an amount measurement as well as a ______ measurement.
width
scent
length
time

Explanation:

When measuring air - pollutants, amount is one aspect, and time is also an important factor as pollutant levels can vary over time. Width, scent, and length are not typical measurements related to air - pollutant measurements by the EPA in the context of the given question.

Answer:

D. time