<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>
Answer:
Global warming is the unusually rapid increase in Earth's average surface temperature over the past century primarily due to the greenhouse gases released by people burning fossil fuels.
The small intestines give nutrients to the blood
