Conservationists have unveiled plans to preserve and protect the world's most important species of coral, in a response to increasing threats that they say will lead to "functional extinction" within decades．
Led by scientists at the Zoological Society of London, the Edge Coral Reefs project has identified 10 coral species in most urgent risk of becoming extinct．The scientists say that reefs are under pressure from a variety of threats including rising sea temperatures due to climatic instability, increased acidity（酸性）, overfishing and pollution．
The Edge plan, which focuses on the most evolutionarily distinct and globally endangered species , will take a regional approach to conservation．This means focusing on the "coral triangle" around the Philippines, the West Indian Ocean around the Mozambique channel, and in the Caribbean channel．
"Coral reefs are threatened with functional extinction in the next 20-50 years, due predominantly to global climatic instability," said Catherine Head, coordinator of the reefs project．"In these regions, we'll be supporting and training in-country conservationists to carry out research and implement targeted conservation actions," she said．"Their projects will last initially for two years．We provide them with a whole host of tools to carry out their projects including funding and intensive training．" She added．
Coral reefs are the planet's most diverse marine ecosystem（生态系统）, known as the rainforests of the oceans．Despite taking up under 0．2% of the ocean floor, they provide food and shelter for almost a third of all sea life．If we lose the ecosystems, we lose not only the biodiversity （生物多样性）, but we also lose the capability of people to obtain income and food from coral reefs．
Climatic instability, which leads to rising sea temperatures, causes corals to bleach．Bleaching occurs when sea temperatures rise and this causes the coral tissue to expel their symbiotic algae called zooxanthellae - these are what give the coral their colour．Bleached corals often die if the stress continues．Among the 10 species chosen to start the Edge project are the pearl bubble coral, a food source for the hawksbill（玳瑁）turtle, and the Mushroom coral, which supports at least 15 brightly colored fish．
小题1:What does the first paragraph mean in the passage ?

A．Conservationists planned to preserve and protect some extinct corals years ago．

B．Conservationists have banned plans to protect endangered corals for years．

C．Conservationists are going to protect corals that are dying out in several ten years．

D．Conservationists have made plans to protect corals from being extinct in ten years．

小题2:What will probably happen to coral species with the increasing threats?

A．Decrease．	B．Losing functions
C．Disappearance．	D．Existence

小题3:Which of the following statements about the Edge Plan is TRUE?

A．The Edge Coral Reefs project was carried out by American scientists．

B．The plan concentrates on the channels to protect the endangered species．

C．The Conservationists have carried out the Edge plan for many years to protect the corals．

D．Ten coral species chosen by the project are at the greatest risk of becoming extinct．

小题4:Which of the following will be the consequence of coral extinction in the passage?

A．We will keep the balance of the marine ecosystems．

B．About one third of the marine species can't survive．

C．Man can benefit more from corals．

D．We will lose the rainforests on our earth．

小题5:What is the best title of the passage?

A．Climatic Instability and Coral Extinction

B．Reasons for Coral Functional Extinction．

C．A Plan to Save Coral from Extinction

D．A Research about Endangered Coral Reefs．