<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:
C. because the common goal of basic science is to understand how things work, whether it is a cell, an organism, or a entire ecosystem.
