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.
One 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 is here: Researchers did experiments on kids in order to find out _ .
Explanation: 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: Article: Australian sleep researchers have developed a set of hi-tech "sunglasses", described as the world's first "time control" glasses, which can imitate sunlight patterns. The team, from Flinders University, in Adelaide, says the glasses send out a soft green glow that helps a traveller adapt to changing sleep patterns and time zones in "small steps". It targets a part of the brain that regulates the human body-clock, by sending signals to the rest of the body that help it slowly realise it is in a different area of the world. It has been suggested the device, called the "Re-Timer", is currently the only wearable body clock adjustment system commercially available. Scientists say the device, officially launched in South Australia, can help ridf the negative effects of long-timel travel and bring new relief to insomnia sufferers, shift workers and even teenagers. "The light from Re-Timer stimulates the part of the brain responsible for regulating the 24-hour body clock," said Prof Leon Lack, its chief inventor. Extensive research has shown that green light is one of the most effective wavelengths for influencing the body clock. The battery-powered device, which retail for PS162 in Britain, then sends signals that cause the production of hormones and daily cycles known as circadian rhythms . Those people who want to sleep peacefully, but wake earlier, should wear it for 50 minutes in the morning for three days. Those who want a lie- in, should wear it for the same time before bed to delay the body clock. The device, which is powered by an inbuilt rechargeable battery, can also be worn as sunglasses during daily tasks such as reading or using a computer. "The glasses have been designed to be user friendly and comfortable to wear so people can go about their normal activities wearing them at work or at home," he said, adding they had been designed based on 25 years of university research. It is estimated that up to 94 per cent of long-time travellers suffer from jet lag because the body becomes confused to travelling through different time zones. So the glasses are good news to them. It uses the outside world as indicators as to whether it should be awake or asleep including factors such as light, silence or noise. Airlines are said to be seeking a "silver bullet" for the tiredness and confusion that often follow a long-timel flight and are in discussions to buy the device.
Answer: motivating part of the brain
Solution:
The "time control" glasses work by _ .