Concentration is the amount of substance per defined space. Another definition is the ratio of solute in a solution to either solvent or total solution. :)
Answer:
All energy sources have some impact on our environment. Fossil fuels—coal, oil, and natural gas—do substantially more harm than renewable energy sources by most measures, including air and water pollution, damage to public health, wildlife and habitat loss, water use, land use, and global warming emissions
Fermentation that causes dough to rise is alcoholic acid, and this is when the alcohol is rising and leaving the dough. In a human, we don't have alcohol, or else we would be drunk after we work out. Instead, we have Lactic Acid fermentation, and this is when you use up too much oxygen, so fermentation make us really tired or else, we wouldn't be able to keep working out.
