Answer:
A control group is a set standard so that comparisons can be made to see what your experiment did. The experimental group is the group that has been changed. A control group also allows you to determine your variables.
Explanation:
in the stars are three main system so I shall say the difference is that they are not in right position
The answer is chemical energy
Answer:
specialization. please follow me I'm new here
Answer:
the major source is moving water. option 3