What is parasympathetic nervous system

It regulates the body’s rest and digest mechanism. Once stress is reduced the system helps the body return to its normal state and conserve energy by slowing the heart rate, and reducing blood flow to the muscles.

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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.