Answer:
A control variable is the variable in the experiment that does not change.
Explanation:
If you are testing how seeds grow in different types of water, and you add 1tbps of salt to one pot of water with the plant, and then added 2tbps to another pot of water with the plant. The control variable in this experiment would be the water with no salt because it was not altered.
FYI I did not pull from google. Good luck!
Hi! The answer is A, those who are sexually active
Probably a lake because it has the possibility to be the largest body of water
