Deciduous trees have... Leaves that never fall

Leaves that fall once a year

Pine needles that fall once a year

Pine needles that never fall

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.