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: Earthquake is not an unfamiliar word to us as it is frequently covered on the news report. However, I never have the idea that it will take place in my city. But the truth is that it happened. When the building began to shake, I thought it was dizziness caused by long-time nonstop work and colleagues also kept silent till one of them shouted, "The chair is shaking." Then we came to understand it was not personal feelings, and we started to find the reason--the weak foundation of the building, or earthquake (in a joking tone), but we still kept doing what was in hand. It was kind of _ when I looked back, because of our slow reaction and stupid response. It was said that the staff in another building next to us all ran out of the building with their handbags; some of them even drove away. On hearing that, I thought it was a bitexaggeration . Did they really have to do so? It was only 20-second mild shaking. But now, when I totally get to know what happened, I change my mind. It is not over-reacting, but natural self-protection response. Luckily it's only the aftershocks; otherwise I guess I would be frightened to death. The aftershocks make me think what I'm going to do in case of earthquake, which I would never give a second thought before. I don't know what's on their mind for people who are on the spot of the earthquake, be frightened, at a loss, or simply running away, or trying to get contact with friends or... It is hard to imagine the picture and even harder to imagine what's next. For the first time, I have the feeling of insecurity. Humans are so fragile when they face the sudden disasters.
Answer: Because there were no signs of earthquake at that time.
Answer:
Why did the author and his colleagues still keep working when the building began to shake?