They respond negatively.
No. Sand and gravel are two different terms for describing sediment size. Gravel is a size up from sand.
sand is a base and gravel is a acid
Sand and gravel are dug out of open quarries on the surface.
Sand and gravel can be separated by sifting them through a mesh, that will allow the sand to fall through, but will hold back the gravel.
Gravel and sand are broken rocks.
Sand and gravel together
Sand and gravel are dug out of open quarries on the surface.
Sand is more fine than gravel
The gravel and sand filter out smaller particles from the water
SAND SAND
You're talking about driveways, right? As in your zoning says you can have either a concrete drive, an asphalt one or a sand & gravel one? Gravel is crushed rock, and they say "sand and gravel" because gravel almost always has sand in it. Crushed loose bedrock would be fine.
Yes the Sahara is a huge expanse of sand and gravel.