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.

Input: Consider Input: Article: In 1901, H.G. Wells, an English writer, wrote a book describing a trip to the moon. When the explorers landed on the moon, they discovered that the moon was full of underground cities. They expressed their surprise to the "moon people" they met. In turn, the "moon people" expressed their surprise. "Why," they asked, "are you traveling to outer space when you don't even use your inner space?" H.G. Wells could only imagine travel to the moon. In 1969, human beings really did land on the moon. People today know that there are no underground cities on the moon. However, the question that the "moon people" asked is still an interesting one. A growing number of scientists are seriously thinking about it. Underground systems are already in place. Many cities have underground car parks. In some cities, such as Tokyo, Seoul and Montreal, there are large underground shopping areas. The "Chunnel", a tunnel  connecting England and France, is now complete. But what about underground cities? Japan's Taisei Corporation is designing a network of underground systems, called "Alice Cities." The designers imagine using surface space for public parks and using underground space for flats, offices, shopping, and so on. A solar dome  would cover the whole city. Supporters of underground development say that building down rather than building up is a good way to use the earth's space. The surface, they say, can be used for farms, parks, gardens, and wilderness. H.G. Wells' "moon people" would agree. Would you? 
 Answer: lived in so many underground cities

Output: The explorers in H. G. Wells' story were surprised to find that the "moon people"   _  .


Input: Consider Input: Article: Five times in the earth's history, some three-quarters of all living species disappeared forever-and within a short period of time. Those species losses stand for a major change in the planet's ecology . Clues to these changes can be seen in the fossils and rock layers. Today, human activities are driving species to die out at a rate never seen before. And this loss of species really does matter, said Anita Narwani. She works at the University of Michigan in Ann Arbor. That's because the diversity of species in an ecosystem provides people with all types of services we can't do without. Trees provide oxygen for us to breathe. At the same time, they remove carbon from the air which is a cause of global warming. Plants help clean air and water. Animals move seeds from one area to another. A broad range of living resources also provides people with food, shelter and medicine. Narwani wanted to find out how important the diversity of species is for people. So she teamed up with other ecologists to review more than 1,700 studies. They found that more diverse parts of the earth tend to do well in things like removing carbon and providing us with wood and other natural resources. _ were also better at keeping fisheries large and healthy so that they could feed many people. Unfortunately, the diversity of species is in steep drop. It is too soon to say that the earth is undergoing a sixth mass extinction, Narwani said. She said a mass extinction means the loss of 75 percent of species over 2 million years or less. We haven't lost that many - at least not yet. But according to her, if species losses continue so fast, such a mass extinction could occur in just 300 years. The new findings highlight the potential for humans to use up many of the resources on which we now depend. As people learn more, however, they can take steps to lessen those risks. People should protect ecosystems so that they can continue to provide us with their services. 
 Answer: many people know the importance of protecting wildlife

Output: Narwani and her team found that  _  .


Input: Consider Input: Article: The gift of being able to describe a face accurately is a rare one, as every experienced police officer knows to his cost. As the Lancet put it recently, "When we try to describe faces precisely, words fail us, and we resort to identikit   procedures." Yet, according to one authority on the subject, we can each probably recognize more than 1,000 faces, the majority of which differ in fine details. This, when one comes to think of it, is a tremendous feat, though, curiously enough,  ly little attention has been devoted to the fundamental problems of how and why we acquire this gift for recognizing and remembering faces. Is it an inborn property of our brains, or an acquired one? As so often happens, the experts tend to differ. Thus, some argue that it is inborn, and that there are "special characteristics about the brain's ability to distinguish faces". In support of this, they note how much better we are at recognizing a face after a single encounter than we are, for example, in recognizing an individual horse. On the other hand, there are those, and they are probably in the majority, who claim that the gift is an acquired one. The arguments in favor of this latter view, it must be confessed, are impressive. It is a habit that is acquired soon after birth. Watch, for instance, how a quite young baby recognizes his mother by sight. Granted that his other senses help - the sound, his sense of smell, the distinctive way she handles him. But of all these, sight is predominant. Formed at the very beginning of life, the ability to recognize faces quickly becomes an established habit, and one that is, essential for daily living, if not necessarily for survival. How essential and valuable it is we probably do not appreciate until we encounter people who have been deprived of the faculty. This unfortunate inability to recognize familiar faces is known to all, but such people can often recognize individuals by their voices, their walking manners or their spectacles. With typical human ingenuity, many of these unfortunate people overcome their handicap by recognizing other characteristic features. 
 Answer: few people can give exact details of the appearance of a face


Output: It is stated in the passage that   _  .


