Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.
Living coral reefs are amazing ‘cities beneath the sea’ that are full of life. The reefs develop well in the warm oceans near the Equator. The Great Barrier Reef, in Australia, is the largest reef in the world. It is 2,000 kilometres long. Each year, thousands of visitors come to see this remarkable world beneath the waves. However, there are rules - visitors can only visit 5% of the reef. In this way, they can still enjoy the reef while it remains protected for future generations.
In recent years, a number of dangers have threatened coral reefs and the life that depends on them. One of the biggest threats is an illegal way of fishing that explodes bombs in the water to kill as many fish as possible. It kills most living things and causes great lamage to the reef's structure.
Fishing with an extremely dangerous chemical called cyanide is another threat to reefs, particularly in the Philippines. Fishermen put this poisonous chemical into the reef water because it stuns the fish and they can't move. They catch the fish easily and then sell them for big money to aquariums or restaurants. The chemical they use kills coral polyps, and causes large areas of the reef to die. Water pollution also damages reefs. In addition, warmer water in the oceans has been causing many areas of reefs to turn white. Biologists are worried that further warming may damage coral reefs even more.
Threats to coral reefs are serious, but there is reason to hope that they will survive. Coral reef conservation can help these tiny coral polyps, which have survived natural threats for millions of years, to rebuild the damaged reefs that so many ocean creatures and plants depend on.
