缺词填空 Why does the Leaning Tower of Pisa in Italy lean? It leans because of a mistake. It has leaned almost since the day the builders b 1 it. In 1774, the people of Pisa in Italy wanted to build a bell tower. They wanted the tower to be the m 2 beautiful bell tower in Italy. The city needed a bell tower because the church(教堂) did not have o 3    . As soon as the first floor of the building was finished, the tower started to lean. Builders t 4 to make the building straight again as they added more floors, but the leaning tower got w 5 as the tower grew. It took about 180 years to finish the tower. Today, the leaning tower has eight f 6 It is 54.5 meters t 7    . And it leans almost 4 meters to one s 8 . The tower is also sinking(下沉) into the g 9 on which it was built. Every year, the tower leans a 10 1.7 cm.