Answer:
The source of energy for chemosynthesis is energy liberated from a chemical reaction (the oxidation of an inorganic substance)
Explanation:
https://sciencing.com/source-energy-chemosynthesis-6681808.html
Your answer is wall. A cell wall...
Group of people could have a very specific challenge having to do with the person or the task - need to watch the same person to see how they change; Ex: some type of physical or cognitive challenge and want to see their progression
Hope this helps