Read the text and choose the appropriate answer.
In some parts of the world, air pollution is a big problem. Pollution is caused by burning fuel in vehicles and buildings. The smoke from burning fuel has poisonous gases and dust that make the air dirty. Why else is pollution bad? The dirty air hurts people, causing more colds, coughs and diseases of the heart and lungs. It also harms plants and animals and makes clothing and buildings dirty.
Which is true to the text?
Air pollution is not much of a problem.
Smoke carries poisonous gases.
Air pollution helps people stay healthy.
Burning fuel comes from dust.
Dirty buildings cause pollution.
