Which of the following would be examples of pollution?
1) A factory releases its waste into a river, where it affects the amount of oxygen in the water.
2) Trees used to control soil loss begin to spread over large areas, killing native trees.
3) Leaking gasoline tanks add substances to water deep in the ground.
о
1 and 3
о
_ 1, 2 and 3
O
2 and 3
1 only