In this task, you're given an article and an answer. Your task is to generate the fill-in-the-blank question for this answer based on the given article. The blanks are always at the end of the question, and can be filled with more than one word or phrase.

[Q]: Article: We always read reports about costs of oil going up and we will think this is our most valuable material. However, water is the most valuable resource . People in the Middle East are more worried about this than oil. Maybe the next war will be about water. In the future, to control the quality and quantity , you will use different water for different usages. The water used to wash your car, water your flowers or wash your clothes doesn't need to be as clean as the water you drink. One in five people live in countries without enough fresh water and in 25 years, the number is believed to be one in every three people. Our world population is increasing. What do you suppose this will suggest for us in the future? Population control? Traditional management of the water industry has been out of date since the 1990s. When technologies develop so rapidly in the world, we have loads of information for technologies in the business world, but in the water industry we don't have any. Britain and France have already taken measures to successfully improve their water industries. All the water services in Britain have been provided by private companies since 1991. Since then, improvement has been made in the rules for their water quality and pricing. What can you do now for the future? Using water more efficiently in your house can make a great difference not only to the world but to your money. Even if you don't have to pay much now, you will when you start to pay big prices for different water usages.
Answer: the world population is growing up.
[A]: Water shortage is getting more serious because _ .

[Q]: Article: The Tories would allow children to go to school for ten hours a day and on Saturday mornings to improve the performance of poorer pupils and help working parents. Schools spokesman Michael Gove declared plans yesterday to give disadvantaged children more classroom time to help them catch up. Longer school days could also be popular with parents who struggle to fit 3pm school finishing times around work, he said. Mr. Gove gave out the success of a U.S. plan where teenagers from poor backgrounds attend school from 7.30 am to 5pm. "I believe that having children in school for longer, particularly if they come from disadvantaged backgrounds can help them to achieve more in academy, " he told the annual conference of the Association of Teachers and Lecturers in Manchester. He pointed out that it was up to schools alone to decide whether to open longer, or at weekends. But he was greeted with laughter from delegates when he said the plan would really work only with the active support of teachers. ATL general secretary, Dr Mary Bousted, said, "The last thing we need to be doing at the present time is increasing teachers' working hours. Teachers already work the most unpaid overtime of any public sector profession. If we want Saturday schools then we need more teachers doing the extra hours, not the same teachers working longer and becoming tired." Meanwhile Mr Gove's idea is likely to alarm those concerned about the erosion( )of family time. Margaret Morrissey, founder of the lobby group Parents Outloud, said, "What we should be doing is supporting these children within the school week."
Answer: studies
[A]: The successful example given by Mr. Gove suggests that having children in school for longer, can improve their _ .

[Q]: Article: Exhausted and unhappy, you still have to squeeze a smile to your friends, or teachers. That's just life, you may think. But new research suggests that putting on a fake smile can worsen people's mood and even lower work efficiency. Lead researcher Brent Scott with other researchers studied a group of bus drivers for two weeks. They tried to find out what happened when the drivers were involved in "surface acting" or fake smiling, and the opposite, "deep acting" which means people put on real smiles by recalling pleasant memories or thinking about their current situation more positively. The results showed that on days when drivers were forced to smile, they felt depressed and didn't want to work. On days when they smiled due to positive thoughts, their mood improved a lot as well as their work efficiency. The research goes against the popular belief among companies that employees should be cheerful to customers at all times. They include employees of shops, banks, call center workers and others who have face-to-face contact with members of the public. "Smiling for the sake of smiling can lead to emotional exhaustion and coldness, and that's bad for the organization," Scott told the Daily Mail. The study also showed that women were harmed more by fake smiling than men. Their mood and work performance both worsened more. But they were helped more by deep acting -- their mood became better and they worked more efficiently. However, while deep acting seemed to improve mood in the short term, Scott says it's not a long-term solution for unhappiness. "There have been some suggestions that if you do this over a long period that you start to feel inauthentic ," Scott said. "You may be trying to cultivate positive emotions, but at the end of the day you may not feel like yourself anymore."
Answer: thinking in a positive way helps with work efficiency
[A]:
Brent Scott and others' experiments on bus drivers suggest that _ .