Normally, in the process of osmosis, the net flow of water molecules into or out of the cell depends upon differences in the: A Concentration of water molecules inside and outside the cell
B. Concentration of enzymes on either side of the cell membrane
C. Rate of molecular motion on either side of the cell membrane
D. Rate of movement of insoluble molecules inside the cell

I think the answer for this is A.

heat a spark and oxygen

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.