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: A new study warns that about thirty percent of the world's people may not have enough water by the year 2025. An American organization called Population Action International did the new study. It was more than three hundred and thirty-five million people lack enough water now. The people live in twenty-eight countries. Most of the countries are in Africa or in the Middle East. Population Action International researcher Robert Engelman says by the year 2025, about three thousand million people lack water. At least 18 more countries are expected to have serious water problems. The demand for water keeps increasing. Yet the amount of water on the earth the same. Mr Engelman says the population in countries that lack water is growing in these countries will continue to increase. The report says lack of water in the future may result several problems. It may increase health problems. Lack of water often means drinking water is not safe. Mr Engelman says there are problems all over the world because of diseases such as cholera that are carried in water. Lack of water also may result in more international conflict. Countries may have to fight for water in the future. Some countries, such as Syria, Sudan, Cambodia, and so on, now get sixty percent of their fresh water from other countries. And the report says lack of water would affect the ability to improve their economies. This is because industries often need a large amount of water. The Population Action International study gives several ways to solve the water problem. One way is to find ways to use water for more than one purpose. Another way is to teach people to be careful not to waste water. A third is to use less water for agriculture. The report also says long-term solutions to the water problem must include controls on population growth.
Answer: At least forty-six
Student:
According to the report, how many countries will lack water by the year 2025?