Answer:
Dark spots appear when the skin cells produce too much melanin. if the original spots were deep, it may be permanent.
Explanation:
Parkinson's disease is a deficiency of the neurotransmitter dopamine. Dopamine is responsible for how the brain deals with stress, especially the fight-or-flight response. Thus, it affects greatly on the movements of the body. Also, dopamine is responsible for information processing. That is why people with Parkinson's disease have trouble in retaining their memories or be in deep concentration.
The best answer to fill in the blank would be ''Bystander'' because as that role you can go tell any adult or higher authority to stop the fighting so you don't try to be a hero and get yourself hurt as well.