GIẢI THÍCH
When the air is dirty it has become polluted. Air (1) _______ is made up of gases, dust, odors, particles, smoke, fumes, and other substances which can be harmful to humans, animals, plants, and all living organisms. The air is (2)_______ and unclean.
Air pollution affects the Earth's atmosphere. The atmosphere of the Earth is like a blanket of air which protects all life. Without the atmosphere, life would not exist. The atmosphere protects living organisms from the heat of the Sun during the day, and at night it prevents the warm air from escaping. Basically, the atmosphere helps keep the living things(3) _______ Earth from burning up or freezing.
The pollution in the air, though, may affect this 'blanket' and becomes harmful to life on Earth. The substances in the air causing the dirty air (4)_______called pollutants. (5)_______examples of pollutants may include gases called carbon monoxide, nitrogen oxide, hydrocarbons, and others. There may also be sand, dust particles, and other substances that evaporate and become pollutants.
(1) pollution
(2) contaminated
(3) on
(4) are
(5) An