Mucus and saliva contain an enzyme that breaks down the cell wall of many bacteria.
Answer: History
Explanation: The history effect is an experimental research problem,which stems from the likelihood that an observed effect or result in our experiments is as a result of an extraneous affect or factor rather than the applied treatment used in the experiment.
In the scenario above, the group were being taught alphabet as treatment at about the same time when alphabet was being taught on television. Therefore, the result of the experiment may be influenced by the Television program rather than the applied treatment.
The answer is A. Aerobic Training hope this helps
I'm not sure on this one... Maybe Carbon Dioxide?
