Teacher: 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.
Teacher: Now, understand the problem? If you are still confused, see the following example:
Article: Homework can put you in a badmood , and that might actually be a good thing. Researchers from the University of Plymouth in England doubted whether mood might affect the way kids learn. To find out the answer, they did two experiments with children. The first experiment tested 30 kids. Someshapes were hidden inside a different, larger picture. The kids had to find the small shapes while sitting in a room with either cheerful or sad music playing in the background. To test their mood, the scientists asked the kids to point to one of five faces, from happy to sad. Children who listened to cheerful music tended to point to the smiley faces while the others pointed to the unhappy ones. The researchers found that sad kids took at least a second less to find the small shapes. They also found an average of three or four more shapes. In the second experiment, 61 children watched one of two scenes from a film. One scene was happy, and the other was sad. Just like in the first experiment, kids who saw the sad scene acted better compared to the others. The researchers guessed that feeling down makes people more likely to focus on a problem or difficult situation. Not all scientists agree with them, however. Other studies argued that maybe, that cheerful music in the first experiment distracted kids from finding shapes. While scientists work on finding out the answers, it still might be wise to choose when to do your tasks according to your mood. After eating a delicious ice cream, for example, write an essay.
Answer: whether mood affects their learning ability
Solution: Researchers did experiments on kids in order to find out _ .
Reason: It is clearly mentioned in the article that to the check effect of mood on children is the main purpose of the experiment.

Now, solve this instance: Article: There are new findings that not enough sleep may cause people to gain weight. Researchers say a lack of sleep can produce hormonal changes that increase feelings of hunger. In one study, researchers in the United States examined information on more than 1000 people. The people had taken part in a long-term study of sleep disorders. Some people slept less than five hours a night. They had 15 percent higher blood levels of a hormone called ghrelin than people who slept eight hours. And they had 15 percent less of the hormone leptin. Experts say ghrelin helps make people feel hungry; leptin makes you feel full. The scientists say these hormonal changes may be a cause of obesity in Western societies. They note the combination that sleep limitation is common and food is widely available. The results were not affected by how much people exercised. People who are awake longer have more time to burn energy. But the researchers say loss of sleep may increase hunger especially for high-calorie foods, so people gain weight. It seems that, for survival, the body may be designed to store more fat during times with less sleep. Researchers from Stanford University in California and the University of Wisconsin did the study. They found that the best amount of sleep for weight control is 7.7 hours a night.The Public Library of Science published the findings in its journal Medicine . Internet users can read the full study, free of charge, at plos. org.
Answer: making you want to eat more food
Student:
Not enough sleep can cause obesity by _ .