They did not repeat their tests multiple times.
Reason being is using the same stopwatch doesn’t matter and changing the reactants won’t help, and you without a doubt need more than one person collecting the data so,
They did not repeat their tests multiple times is the answer.
Answer:
Actually, many single-celled organisms have a structure that facilitates mobility within the cell's environment. These often take the form of flagella, thin structures that emanate from the cell wall and push into the outer environment
Explanation: