in the building的意思及用法？

The Parthenon was a church from 1204 until 1456, when Athens was taken by General Mohammed the Conqueror, the Turkish sultan,who established a mosque in the building and used the Acropolis as a fortress.
麻烦翻译一下这句话，in the building在这句话里是什么意思，为什么要这么用？

23.The fire destroyed ____ was in the building. ( ) tallest building in the town is ( ) Bank of China. The building ___ in our schoolis for us teachers. How many years was spent in building the tower? I thingk there will be more tall building in the coubtry in 5 years.中building为什么加ing Not many years ____,the baiyun Hotel was the tallest building in China. It took us two years______(build)the highest building in the city. the police carried out a through search of the building.为什么用of不用in. the two building,building为何单数？ This kind of material was seldom used in building houses during the