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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.

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?
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.

New input: Article: Mrs. Blake teaches English in a large school in the inner area of a big city on the west coast. Even since she was a young girl, she has wanted to become a teacher. She has taught eight years now and hasn't changed her mind. After she graduated from high school, she went on to college. Four years later, she received her bachelor's degree (BA) in English and her teaching certificate . Then she went to teach in the secondary schools of her state. In the summers, Mrs. Blake takes more classes; she hopes to get a master's degree ( MA ). With an MA, she will receive a higher salary and if possible, she hopes to get a doctor's degree as well. The school day at Mrs. Blake's high school, like that in many high schools in the United States, is divided into one hour each. Mrs. Blake must teach five of these periods. During her free period, which for her is from 2 to 3 P.M, Mrs. Blake must meet with parents, make our examinations, check assignments at all, Mrs. Blake works continuously from the time she arrives at school in the morning till the time she leaves for home late in the afternoon.
Answer: twenty years
Solution:
How long is it since Mrs. Blake graduated from middle school?