The brain loses 5-10 percent of its weight between the ages 20 & 90.
There are different materials of raw water, but also the raw water comes from ponds,rivers, and oceans but they might be good sometimes, and gas not been treated and has bacteria or mold buy that is not good.
This contributes because their lifestyle revolves around food, and if they live near different areas, they will have to search for different types of food.
The answer is the first one because it doesn't create gases and, the third one doesn't even make any sense so its definitely not that one
