<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>
Science can be applied to many things the earth around us. Maybe even technology for example self-driving cars is a part of science!
I believe it is the crust
The last option is the most accurate
Hope this helps!
