We did not use a control group in this experiment. What is the purpose of the control group and how could we have set up with one for this experiment? 

The experiment will be faulty

Explanation:

To set up a control group, you pick individuals at random( so you don't just get a group to be of the same character, or opinion).

The control group is vital in every experiment because, sometimes our hypothesis could be mere coincidence or assumptions. So the control group will be compared to the test group to see if the results are correct. Plus look at it this way, without a control group, your hypothesis wouldn't be a theory.

answer; ///i believe the correct answer is (aids) acquired immune deficiency syndrome;

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.