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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: If you need glasses to read this, you are among the majority of Chinese students. That's because most students in China are short-sighted which means they can only see things close up and distant things will be _ . Four-fifths of high school students wear glasses and now more and more children in primary school need glasses, too. This epidemic of poor eyesight has two very simple causes: too much time spent indoors studying and too little time spent outdoors playing. Reading and writing for hours and hours, sometimes in poorly lighted rooms, causes eyesight to weaken. But students have to do this because there is so much pressure on them to succeed in school. And because they spend so much time indoors at school and at home, they have less time to spend outdoors enjoying the sun. The sun, as a consequence, is important in developing good eyesight. Exposure to daylight releases a chemical in the eyes that prevents, or at least delays, short-sightedness. According to a study by Ian Morgan of Australian National University, Australian children and Chinese children have the same level of eyesight before they start school, but once they enter primary school, Chinese children only spend about an hour a day outside, while Australian children spend three to four hours each day in the sunshine. The result is that while about 40 percent of Chinese primary school students need glasses, only three percent of Australian children do. Wearing glasses may not seem like a big deal. For some, wearing glasses can even be an opportunity to make a fashion statement. But poor eyesight at a young age can have serious long term consequences. As you get older, your eyesight can worsen and lead to things like macular degeneration , a condition of the eyes for which there is no cure and which can eventually lead to blindness. With all that in mind, don't you think it's time to give your eyes a break? Try spending a little less time inside and go for a walk in the park, instead. It's the healthy thing to do and your eyes will thank you for it.
Answer: They should stay longer outdoors.
Solution:
How should the students protect their eyesight according to the passage?