The Leaning Tower of Pisa is a very famous building in the city of Pisa, Italy. Construction was started in 1173 and completed in 1372. It took nearly 200 years to be completed. The tower has eight levels. Different types of stones and marbles were used to build this tower. The building isn’t straight but leans over one side. The highest side of the tower is 56.67 metres and the lowest side is 55.86 metres. Many architects said the tower was in danger of falling so they suggested straightening it. In 1990, the tower was closed to the public and they started to restore it by removing some soil under the higher side of the tower. It was reopened to the public again in 2001. The architecture of the tower is very beautiful and it is one of the most popular tourist attractions in Italy. a) How long did it take to construct the Leaning Tower of Pisa? b) What was used to build this tower? c) Why did many architects suggest straightening the tower? d) How did they restore the tower?