They all burn gasoline

They all burn coal

They all burn wood

They all burn fossil fuels

People being poisoned by drinking water

Fish and birds in freshwater habitats dying off

People receiving acid burns on their skin

Whales and dolphins dying off in the oceans

Life-sustaining

Harmful

Pleasant

Foul-smelling

Air pollution is most serious in areas with many homes, factories, and offices

Air pollution never affects rural areas

Animals don’t cause any air pollution

Cities attract air pollution because they extend so high in the atmosphere

Smog makes it difficult to breathe; acid rain wipes out natural habitats

Smog is caused by burning fossil fuels; acid rain is caused by cow burps

Scientists agree that smog is caused by humans, but disagree over the cause of acid rain

Smog only affects cities; acid rain only affects rural areas