Pollution is any contamination of the environment which causes harm to the environment or the inhabitants of the environment. There are three main kinds of pollution. Air pollution can be caused by liquids, or gases that make the air harmful to breathe. There are two main types of air pollution: primary and secondary. Primary pollutants enter the air directly, like smoke from factories and car exhaust. Secondary pollutants are chemicals that mix together to pollute the air, like mixtures of emissions from vehicles and factory smoke that change to form more dangerous pollutants in the air and sunlight. Soil pollution can be caused by pesticides, leakage from chemical tanks, oil spills, and other chemicals which get into the soil by dumping or accidental contamination. Soil pollution can also cause water pollution when underground water becomes contaminated by coming into contact with the polluted soil. Water pollution can be caused by waste products, sewage, oil spills, and litter in streams, rivers, lakes, and oceans. Some scientists believe that water pollution is the largest cause of death and disease in the world, causing about 14,000 deaths in the world each day. It is not possible for anyone to predict the exact timing and effects of global pollution and global climate change brought about by pollution. There is general agreement by scientists that the global climate will continue to change, the intensity of weather effects will continue to increase, and some species of animals will become extinct. 1. According to the passage, what is the most suitable title? A. Solutions to pollution B. Environmental impacts C. Environmental issues D. Causes and effects of pollution 2. What kind of pollution is considered as the cause of the most death and disease? A. Water pollution B. Soil pollution C. Air pollution D. None of the above 3. What is NOT a cause of soil pollution? A. Pesticides B. Chemicals C. Exhaust fumes D. Oil spills 4. What kind of pollution may oil spills cause? A. Water and soil pollution B. Air pollution C. Soil pollution D. Water pollution 5: According to the agreement of scientists, what is NOT environmental effect caused by pollution? A. Global climate change B. Disappearance of the rain forests C. Intensity of weather effects D. Animal extinction 6. The word “increase” has the closest meaning: A. get over B. take care of C. go up D. eliminate