The answer is two.
About 90 percent of mother's milk is water. A baby drinks up to one liter of milk per day. The simple math says it is important for a mother to take almost one liter of water for the milk and one more for her body to be hydrated. This is 2 liters per day in total. Of course, the more is the better, so drinking up to 3 liters will help the mother to stay hydrated.
<span>The substance that serves best to keep our skin smooth and protected is Keratin. Keratin is a fibrous structural protein and is the protein that protects epithelial cells from damage or stress. Keratin is insoluble in water and organic solvents</span>
I believe its molecular biology because the it is about nucleic acids, carbohydrates, lipids and protein and they are related to DNA and RNA