when excess fertilizers wash off of the nearby farms and into the lake, they become food for the algal blooms that can plague the lake in the summer. So, reducing fertilizer use and preventing runoff directly into the lake would be one way of reducing eutrophication.
We breath oxygen because it is needed to burn fuel [ sugars and fatty acids] in our cells to produce energy. Oxygen is also brought into the lungs via breathing; where it is transported by red blood cells to the entire body to be used to produce energy. The food we eat gives us protein, sugars, vitamins etc. for energy
Both the temperature and the pressure increase.
They can all make you ill and be dangerous for the body