Nhận biết (M1)

Coral reefs occupy less than one percent of the ocean floor, yet they support roughly a quarter of all known marine species. This disproportionate biodiversity arises from the reefs' intricate three-dimensional structure, which provides countless niches in which organisms can feed, shelter, and reproduce. When a reef degrades and that structure collapses, the resulting loss of habitat can trigger declines throughout the entire community that depends on it.

Which choice best states the main idea of the text?

• A.

  Coral reefs cover only a very small portion of the ocean floor.

• B.

  The structural complexity of coral reefs underlies both their rich biodiversity and their vulnerability.

• C.

  Most marine species are unable to survive anywhere except on coral reefs.

• D.

  Reef degradation is caused primarily by rising ocean temperatures.