Air pollution is a cause of ill-health in human beings.

• True (The text states that air pollution causes ill-health in humans, particularly lung diseases.)

There are no laws limiting the amount of smoke that factories can produce.

• False (The text mentions that in many countries, there are laws limiting the amount of smoke factories can produce.)

Doctors have not yet proven that air pollution causes lung diseases.

• False (The text states that doctors have proved that air pollution causes lung diseases.)

The gases from the exhausts of cars have reduced air pollution in most cities.

• False (The text states that gases from car exhausts have increased air pollution in most cities.)

The lead in petrol produces a harmless gas.

• False (The text mentions that the lead in petrol produces a poisonous gas.)

Children who live in areas with a lot of lead in the atmosphere cannot think as quickly and are clumsy when using their hands.

• True (The text states that children in areas with high lead levels cannot think as quickly and are clumsy with their hands.)