Australia said on Friday that it had done enough to prevent the UN from listing the Great Barrier Reef ,the world's biggest coral reef ecosystem ,as being'in danger'* The Great Barrier Reef covers an area of 348,000 square kilometers off Australia's east coast and ontains some 2,500 smalll reefs.Its width ranges between 60 and 250 kilometers.It is a collection of ore than 2 , 900 coral reefs,600 continental islands,and thousands of sea species ,making it one of the world's most complex and varied ecosystems. It was listed as a World Heritage Site in 1981 .But in 2011 UNESCO declared"extreme concern"at the approval of natural gas processing and port facilities within the site and afterwards warned the reef could be considered"in danger".Worried about planned coastal developments,including ports,UNESCO is set to announce overnight a draft decision on the site,which is rich in sea life. "They can see we are doing real work to improve the reef,"Environment Minister Greg Hunt told the Australian Broadcasting Corporation."I firmly believe that we're making once in a century changes to ensure that a century from now,the reef won't just be as it is,but will be better and stronger than it has been since European settlement." Australia has recently ordered a ban on the century-old practice of emptying dredge waste which environmentalists smakes corals and seagrasses die because of lack of airacross most of the reef,and funded efforts to improve water quality. Queensland State,the gateway to the reef,has also promised to introduce laws to limit port develop ment as it balances environmental concerns with the needs of the resources industry What might cause the Great Barrier Reef"in danger"?
.Sudden climate change . .The coastal construction* .The polluted corals and seagrasses. The approval of natural gas processing*
Question: Australia said on Friday that it had done enough to prevent the UN from listing the Great Barrier Reef ,the world's biggest coral reef ecosystem ,as being'in danger'* The Great Barrier Reef covers an area of 348,000 square kilometers off Australia's east coast and ontains some 2,500 smalll reefs.Its width ranges between 60 and 250 kilometers.It is a collection of ore than 2 , 900 coral reefs,600 continental islands,and thousands of sea species ,making it one of the world's most complex and varied ecosystems. It was listed as a World Heritage Site in 1981 .But in 2011 UNESCO declared"extreme concern"at the approval of natural gas processing and port facilities within the site and afterwards warned the reef could be considered"in danger".Worried about planned coastal developments,including ports,UNESCO is set to announce overnight a draft decision on the site,which is rich in sea life. "They can see we are doing real work to improve the reef,"Environment Minister Greg Hunt told the Australian Broadcasting Corporation."I firmly believe that we're making once in a century changes to ensure that a century from now,the reef won't just be as it is,but will be better and stronger than it has been since European settlement." Australia has recently ordered a ban on the century-old practice of emptying dredge waste which environmentalists smakes corals and seagrasses die because of lack of airacross most of the reef,and funded efforts to improve water quality. Queensland State,the gateway to the reef,has also promised to introduce laws to limit port develop ment as it balances environmental concerns with the needs of the resources industry What might cause the Great Barrier Reef"in danger"?
A. .Sudden climate change .
B. .The coastal construction*
C. .The polluted corals and seagrasses.
D. The approval of natural gas processing*
Answer: