Q: Fact 1: Many corals secrete an exoskeleton that builds up to become a coral reef. Fact 2: Coral Reefs Coral reefs are the jungles of the sea. Given the two facts above, many corals secrete an exoskeleton that builds up to become what?

OPT:
(1). important habitats
(2). jungles of the sea
(3). seaweed
(4). gastropod shells
(5). food and shelter
(6). dolphins
(7). major threat to health
(8). oceans
A:
(2).