Students hypothesized that water pollution affects the growth of fish. in an experiment, they added the same amount of food to ponds polluted by fertilizers and industrial waste. they measured fish growth and found that most fish grow more slowly in each of these environments. what part of their experiment did they forget to include?

The part of which made the experiment gone wrong was because they forget to include of having a group that would serve as the control-this is essential in their experiment so that they may be able to determine the effects of the growth of fish in different environments but because they don’t have the group to serves as control, they only have found out that all fishes grow slowly despite with given different environments.