A paragraph states: 'Coral reefs cover less than 1% of the ocean floor yet support 25% of all marine species. They provide food and shelter for thousands of fish, invertebrates, and other organisms. Without reefs, countless species would face extinction.' What is the main idea?
-
A
Coral reefs occupy very little space in the ocean
-
B
Coral reefs are critically important ecosystems despite their small size
-
C
Many marine species would become extinct without coral reefs
-
D
Coral reefs shelter fish and invertebrates