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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.
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Article: For a commuter rushing to catch a train, a minute can mean the difference between dinner with the family and leftovers in the microwave. What most passengers don't realize is that their minute is already there. Every commuter train that departs from New York City -- about 900 a day -- leaves a minute later than scheduled. If the timetable says 8:14, the train will actually leave at 8:15. In other words, if you think you have only a minute to get that train -- well, relax. You have two. The courtesy minute, in place for decades and published only in private timetables for employees, is meant as a grace period for those who need the extra time to get off the platform and onto the train. "If everyone knows they get an extra minute, they're going to waste time doing unimportant things," explained Marjorie Anders, a spokeswoman for the Metro-North Railroad. Told of this article, Ms. Anders laughed. " _ !" she said. Entirely hidden from the riding public, the secret minute is an odd departure from the railroad culture of down-to-the-second accuracy. The railroad industry helped invent the concept of standard time, and time zones were established in the United States in the 1880s, 35 years before they were written into law. And most commuters know their train by the precise minute it departs. The trains quickly make up the minute: at all other stops, the public timetable prevails. The phantom minute does not exist at commuter railroads in Chicago, Los Angeles, Philadelphia, or San Francisco. But in New York, the secret minute dates back decades. "That's been done forever, from my knowledge," said Jack Swanberg, 70, an unofficial historian of Metro-North. "I was the trainmaster starting in 1970 and I'm sure it's been the case since 1870 for all I know."
Answer: prevent the passengers' idleness
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The courtesy minute was hidden from the public to _ .

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Article: A person who is deaf when he is born is usually dumb as well. There may be nothing wrong with his mouth and tongue, but he cannot speak. This is because he cannot hear people, so he has nothing to imitate . He may try to make sounds himself, but cannot hear his own voice. However, even though he finds it difficult to speak and cannot hear, he can learn to read. Nowadays such persons can also be taught to speak because we have modern methods and equipment, but we did not have these when Helen Keller was born. Even with modern methods and equipment, however, it is not easy for deaf children to learn to speak, though most of them succeed. When a child is deaf and blind as well, it becomes much more difficult, though it is possible. Helen Keller was born in 1880. She became very ill at the age of nineteen months. Medical knowledge was not as great then as it is now. She did not die but lost her sight and hearing. As a result, she became dumb as well. Her parents did their best to teach her, but she couldn't speak by the age of six. Then, in 1887, a teacher, Miss Sullivan, came to live with her. Miss Sullivan herself had been blind. She had been partly cured. Though she could not see very well, she was not blind. Helen was a difficult pupil at first, but in a month Helen had learned how to understand signs and how to make them herself. At last in spite of her great difficulties, Helen learned to read, write and speak, even though she was deaf and blind. She even went to college and had full education. She wrote many books, and though other people have written books about her, her own books are the ones that best explain how it feels to be deaf, dumb and blind. Her best book is The Story of My Life. Perhaps you have read it. Though it was written in 1902, it is still a very interesting book. Even if you have not read it, you may have heard of Helen Keller.
Answer: he cannot hear other people and he has nothing to imitate
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A person who is deaf at birth is also dumb because _ .

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Article: Nowadays more and more young athletes are taking part in the risky activities called "extreme sports" or "X-sports". In the past young athletes would play baseball. Today, they want risk and excitement -- the closer to the edge, the better. They snowboard over cliff and hike deep mountains. Extreme sports started as an alternative to more expensive sports such as golf. A city kid who couldn't afford expensive sports equipment could get a skateboard and have fun. But now it has become a whole new area of sports, with specialized equipment and high levels of skill. There is even an Olympics for extreme sports, called the winter x-game, which includes snow mountain hiking and ice climbing. What makes extreme sports so popular? Maybe it's because people love the risk. City people want to be outdoors on the weekends and do something challenging. The new equipment is so much better that people can take more risks without getting hurt. Sure there's a risk. Once you go mountain hiking or snowboarding, it's impossible to go back to have riding or skiing. It's just too boring. Now even the older crowd is starting to join in. Every weekend, groups of friends in their early 30s get together. On weekdays they work as computer programmers in the same office. On weekends they hike mountains together. Extreme sports are certainly not for everyone. Most people still prefer to play basketball or watch sports on TV. But it has been a fact that extreme sports are gaining popularity.
Answer: some city kids couldn't afford expensive sports equipment
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Extreme sports started as an alternative to more expensive sports because _ .