Many corals secrete what to form a coral reef?
Chlorophyll salt and water. The area was once underwater Chemical energy aqueous solution Organic compounds gastropod shells hard outer covering
A B C D E F G H
An insect has a hard outer covering called an exoskeleton.
Many corals secrete a hard outer covering that builds up to become a coral reef.
Many corals secrete what to form a coral reef? (A) Chlorophyll (B) salt and water. (C) The area was once underwater (D) Chemical energy (E) aqueous solution (F) Organic compounds (G) gastropod shells (H) hard outer covering