다음 글의 빈칸에 들어갈 말로 가장 적절한 것은? Coral reefs… | [법원직 9급 영어] 16년 1회차 기출문제 상세 페이지

다음 글의 빈칸에 들어갈 말로 가장 적절한 것은? 
Coral reefs are some of the most diverse and valuable ecosystems on Earth. Coral reefs support more species per unit area than any other marine environment, including about 4,000 species of fish, 800 species of hard corals and hundreds of other species. Scientists estimate that there may be another 1 to 8 million undiscovered species of organisms living in and around reefs.        is considered key to finding new medicines for the 21st century. Many drugs are now being developed from coral reef animals and plants as possible cures for cancer, arthritis, human bacterial infections, viruses, and other diseases. Storehouses of immense biological wealth, reefs also provide economic and environmental services to millions of people. Coral reefs may provide goods and services worth $375 billion each year. This is an amazing figure for an environment that covers less than 1 percent of the Earth’s surface.

This biodiversity

Their beauty

Survival skill of coral reefs

Food chain