no.
They are the foundations of natural concrete
It is synthetic, but what we use to make concrete is natural AND synthetic.
Concrete is man-made.
They are the foundations of natural concrete
the minerals are natural resources
Piedmont's Natural Resources is natural gas.
what are the Natural Resources of the ozark rivers
Washington State's forests are one of their natural resources.In the 1800s, coal and oil were highly valued natural resources. Natural resources are often under threats from human activities.
U.S. History GP: Natural Resources
Their natural resources was minerals.
What are the natural resources of Columbia
what is Hawaii's natural resources