Contractors may have a hand in performing the construction labor as well. Contractors commonly work at construction sites. Although a contractor's main concern is hiring qualified subcontractors, she may also perform some of the construction work as well.
The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,300 kilometres (1,400 mi) over an area of approximately 344,400 square kilometres (133,000 sq mi).The reef is located in the Coral Sea, off the coast of Queensland, Australia.The Great Barrier Reef can be seen from outer space and is the world's biggest single structure made by living organisms.This reef structure is composed of and built by billions of tiny organisms, known as coral polyps.he reef is located in the Coral Sea, off the coast of Queensland, Australia. The Great Barrier Reef can be seen from outer space and is the world's biggest single structure made by living organisms.
The  Great Barrier Reef off the coast of Queensland, Australia, is  important for several reasons.    It is the largest coral reef in the world, almost 2000km lo â¦ ng, with  its coral cays and islands spreading over 300,000 square  kilometres.