Air pollution is a growing problem throughout the world. Indoor air pollution is (41) ..one.. of the leading causes of lung cancers. Families in developing countries use open stoves for cooking and heating (42) .....their......... homes. These homes do not have proper ventilation. The smoke, which is (43) .......full........ of chemicals and carcinogens, gets trapped inside where families eat and sleep. Outdoor pollution also (44) .....causes......... disease and illness, especially in industrial cities such as Beijing, China, where cancer is (45) ...the... leading cause of death. China relies heavily on coal, which is considered the dirtiest (46) ........source...... of energy. According to the European Union, only one percent of urban dwellers in China (47) .....breathe........... clean air on an average day. Neighboring countries including Japan and Korea receive much of China's pollution in the (48) .......form...... of acid rain. This pollution results mainly from the coal powdered factories, which produce inexpensive goods (49) ......for..... North American and European consumers. Outdoor air pollution is also a concern in many wealthy countries. Those who live and (50) ...work......... in urban centers such as Los Angeles or Toronto experience many warm days beneath a layer of smog.

Air pollution is a growing problem throughout the world. Indoor air pollution is one of the leading causes of lung cancer. Families in developing countries use open stoves for cooking and heating their homes. These homes do not have proper ventilation. The smoke, which is full of chemicals and carcinogens, gets trapped inside where families eat and sleep. Outdoor pollution also  causes disease and illness, especially in industrial cities such as Beijing, China, where cancer is  the leading cause of death. China relies heavily on coal, which is considered the dirtiest source of energy. According to the European Union, only one percent of urban dwellers in China breathe clean air on an average day. Neighbouring countries including Japan and Korea receive much of China's pollution in the form of acid rain. This pollution results mainly from the coal powered factories, which produce inexpensive goods for North American and European consumers. Outdoor air pollution is also a concern in many wealthy countries. Those who live and work in urban centres such as Los Angeles or Toronto experience many warm days beneath a layer of smog.