Fill in each numbered blank with one suitable word or phrase.

There are three main (1) ______ of pollution: air pollution, water pollution and noise pollution. Air, which is the most important element of our environment for our (2)_______ can be polluted in many ways. Smoke in the air from mills, factories and industry (3) _________. Carbon monoxide, carbon dioxide, and methane, which are all poisonous gases. This leads (4) ______  health problems like asthma and lung diseases, and the thinning of the ozone layer, which (5)_______ us from harmful UV rays. China , the USA, Russia , India, Mexico and Japan are the world leaders in air pollution (6)_______. Water is also polluted by the discharge of commercial and industrial waste. Sewage in drinking water is another (7)______ of water pollution as it contains germs and viruses. The noise of vehicles, mills, and factories can be really unbearable. This kind of constant sound also (8) ______ headaches, tension, (9) _______ stress and migraines. People living next to a building site where there is too much noise can become sick, as they can not sleep or relax. This is (10) _______ noise pollution.

China , the USA, Russia , India, Mexico and Japan are the world leaders in air pollution (6)_______.