12. Is the upward move of
warm air good or bad for the
dispersion of pollutants?

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
The upward movement of air is a
natural of dispersion of
pollutants. air near the ground
hotter because the sun the soil
and the heats the air nearby.
it is less dense, warm air tends to
towards higher and colder
of the atmosphere. Such
helps the dispersion of .