Regulates the volume and pH of the internal environment. The human excretory system maintains homeostasis by removing metabolic waste such as water, salt and metabolite concentrations in the blood.
There are different techniques to reduce friction, similar to 1. Cleaning the surfaces 2. Including lubricants 3. expanding the temperature 4. wetting the surface 5. expelling polluting influences. Egyptian could have moved the square through water, which would be Fluid Friction, and makes it less demanding to move.
True... water and land mostly covers up the earth... go anywhere and there is water...
