Teacher: In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.
Teacher: Now, understand the problem? If you are still confused, see the following example:
Article: There are a lot of public libraries in Britain. These libraries have more than one hundred and fifteen million books, not including those libraries of public schools. Public libraries not only lend books, music records but also help children, patients in hospitals and others to get special play readings, film shows and so on. The first public libraries were founded in about the year 1850. Today's public libraries usually have a reading-room, a lending room and a reference room. The greatest and most famous library in Britain is that of the British Library in London. It was founded in 1973 and has over 10, 000, 000 books. It has nearly every magazine, newspaper and book published in Britain and other parts across the world.
Answer: 10,000,000 or less.
Solution: How many books are there in the British Library?
Reason: In the Article, 10,000,000 is mentioned for the number of books available in the British Library, so this is a good question.

Now, solve this instance: Article: Why does the Leaning Tower of Pisa in Italy lean? It leans because of a mistake. It has leaned almost since the day the tower was built. In 1173, the people of Pisa, Italy, wanted to build a bell tower. They wanted the tower to be the most beautiful bell tower in all of Italy. The city also needed a bell tower because the church did not have one. However, there was a problem. As soon as the first floor of the building was finished, the tower started to lean. Builders tried to make the building straight again as they added more floors, but they couldn't figure out how to make it stop leaning. It took almost 180 years to finish the tower. Since then, the tower has leaned by another millimeter every year. Today, the Leaning Tower has eight floors and is 54.5 meters tall. By 1990, it was leaning by about 4 meters to one side. It was also slowly sinking into the ground. Many people became worried that it would soon fall apart. In 1998, repair works began on the tower, and by the end of 2001, it had been moved back by 45 centimeters. The tower will still lean, however, so it will need to be repaired again---in another 200 years.
Answer: They wanted to build a leaning tower.
Student:
why did the people of Pisa want to build the tower?