Answer: Water is the world's most common acid and base.
Blood cell : Eukaryotic cell
and
Bacteria : Prokaryotic cell.
Friction occurs between two contacting surfaces. The coefficient of friction is very much dependent on the roughness of these surfaces. Some of the many ways in which the coefficient can be lessened or decreased are to lubricate the surface or make it shiny by eliminating the spikes which caused the roughness.
I need a picture plz I don’t know what to answer.