There are many kinds of pollution. Air, water, and land can be polluted. Some pollution is caused by nature, such as foods, forest fires, and volcanoes. People are the major Cause of pollution. We pollute the air with our cars, homes, and factories. Smoke from factories and car exhaust makes the air looks gray and smoggy. Some people cannot go outside when the air is very bad! We pollute the water by dumping garbage and Chemicals in the water. Plants and animals die because of the pollution in the water. We pollute the soil with Chemicals and garbage. We harm the land by cutting down trees in the forest, especially to build roads and new houses without careful planning and thinking. The only way to save our environment is to think about pollution. How can you stop or limit pollution? How do we protect our environment? Conservation is one way to protect our environment. Conservation is the wise use and protection of our environment. We can control water pollution by not producing as much as waste and by proper disposal of sewage and garbage. We can take care of recreation land by cleaning up, after ourselves and not causing more pollution. Carpooling and public transportation will help reduce air pollution. Recycling is a type of conservation. Recycling is reusing items over again or in a new way. Recycling can help us conserve our natural resources so they will last many more years. 38. According to the passage, pollution________ A. is always caused by humans. B. can only be caused by nature. C. is mainly caused by humans. D. may sometimes cause natural disasters. 39. What kind of pollution may a car cause? A. Air pollution B. Water pollution C. Soil pollution D. Light pollution 40. Which of the followings is not an example of soil pollution? A. Land development B. Waste disposal C. Pesticide or fertilizer use D. Exhaust from traffic 41. How can we help save our environment? A. Stop pollution. B. Dump garbage into the river. C. Drive cars everywhere. D. Cut down trees in the forests. 42. How does recycling help the environment? A. It expands landfills. B. It saves natural resources. C. It increases water pollution. D. It causes air pollution. 43. What can we do to help reduce air pollution? A. Walk or bike B. Carpool to work or school C. Use public transport D. All of the above 44. What is the main idea of this article? A. The air is dirty because of cars and factories. B. The soil gets polluted from littering. C. People cause pollution, but they can also stop or limit it. D. Conservation is the only way to stop environmental pollution