When a local farmer found oil bubbling to the surface in one of his fields, he reported the information to a group of scientists. after 30 years of experimentation, the scientists develop a new theory about how oil formed beneath this location. how do you know that this information is really a theory?

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: