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 elfects will continue to increase, and some species of animals will become extinct. (Adapted from BBC) 42. What kind of pollution is considered as the cause of the most death and disease? A. Air pollution B. Water pollution C. Soil pollution D. None of the above 43. What is NOT a cause of soil pollution? A. Chemicals B. Exhaust fumes C. Oil sprills D. Pesticides 44. What kind of pollution may oil sprills cause? A. Air pollution B. Water pollution C. Soil pollution D. Both B and C are correct 45. According to the agreement of scientists, what is NOT environmental effect caused by pollution? A. Global climate change B. Intensity of weather effects C. Animal extinction D. Disappearance of the rainforests