According to the endosymbiotic theory which two protist evolved from a symbotic relationship of organisms which resulted in eukaryotic organisms containing chloroplasts a. paramecium b. red algae c. euglena d. slime molds

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.

not sure if this what   you'r looking for would be percent composition