According to the passage, the Eiffel Tower was built ………

The Eiffel Tower of Paris is a technological masterpiece in building-construction history. When the French government was organising the Centennial Exposition of 1889 to commemo¬rate the French Revolution, a competition was held for designs for a suitable monument. More than 100 plans were submitted, and the Centennial Committee accepted that of the noted bridge engineer Gustave Eiffel. Eiffel's conception of a 300-metre tower of open-lattice wrought iron aroused amazement, but also much scepticism: Would it be attractive? Nothing even half so high had ever been built. An astounding technical achievement, the tower was completed in only a few months and revolutionised the fields of civil engineering and architecture. Perhaps more impressively, the sceptics were proven wrong: it looked beautiful.