Question

what do we call sources of pollutants that are moving?
stationary
mobile

Explanation:

In environmental science, sources of pollutants are classified. Mobile sources are those that are moving. For example, vehicles (cars, trucks) are mobile sources as they can move from one place to another and emit pollutants like carbon monoxide, nitrogen oxides etc. Stationary sources are fixed in one place (like factories, power - plants).

Answer:

Mobile