Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks from 26 to 30.

The Great Barrier Reef is the earth’s largest reef system. At a length of over 2,500 km it is the largest (26) ________ structure. You can even see it from space. However, the reef is in danger of dying. Because of global (27) ________ , the temperature in the atmosphere keeps rising. This also affects the water temperature. When the oceans get too warm the colourful reefs (28) ________ grey and die. The reef is also dying from pollution caused by factories on the Australian and Indonesian coasts.

It’s a pity that we don’t (29) ________ the environment the ways the Aborigines did thousands of years ago. They respected nature, the animals and plants around them. They never killed more animals than they could eat. (30) ________ , when Europeans arrived in Australia they destroyed a lot of things that the Aborigines valued.