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.

Let me give you an 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.
The answer to this example can be: How many books are there in the British Library?
Here is why: In the Article, 10,000,000 is mentioned for the number of books available in the British Library, so this is a good question.

OK. solve this:
Article: Beijing's historic hutong are in danger of disappearing. That's the warning from residents and historians, who have called on authorities to do more to protect this unique part of the capital's culture. In 2000, Beijing still had 1,300 hutong, according to amateur historian Zhang Wei. But he estimates that since then, at least half of them have disappeared. According to regulations, people can report illegal buildings to urban patrol officers, known as chengguan, and buildings found to be illegal will be demolished by force. However, a China Daily reporter found that it was not an easy task, and lots of additional structures built by their owners were found in hutong. Many owners added a second floor or even more floors to their houses, especially in buildings near main streets, in order to rent more apartments and make more money. Zhang, the historian, said that to better protect the hutong, the government should offer more compensation to residents willing to move away. Guo Dazhi, a photojournalist in Beijing, lived in a hutong for nearly 30 years before moving to eastern Chaoyang district. Guo hopes that the government can solve the problem by moving residents out of hutong with policies such as public renting programs. However, the Beijing Commission of Urban Planning said in a report in July that the relocation of residents from old areas was very expensive.According to the report, allocating 10,000 residents costs 1.5 billion yuan .
Answer: Some people build unlawful construction
Answer:
What made Beijing's historic hutong in danger?