What forms soil?
one celled organisms single-celled organisms an external framework erosion from rivers Earthworms Sand dollars The area was once underwater most organisms
A B C D E F G H
Rivers erode the rocks they flow over.
soil is formed by rivers
What forms soil? (A) one celled organisms (B) single-celled organisms (C) an external framework (D) erosion from rivers (E) Earthworms (F) Sand dollars (G) The area was once underwater (H) most organisms