<span>Sumerians built walls using the natural resource they were surrounded with, which was namely clay. They used this clay to create fired mud-bricks, as there was not any other building stone available at the time. However, the clay mud-bricks proved to be a solid structure for town fortification.</span>
Bacteria protects the cell in your intestine and helps us absorb fatty acids. It is harmful because when you have contact with it, the bacteria can reproduce in your body, damaging it and making you sick.
