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.

[EX Q]: Article: For the British, the home is a private place in which he or she goes to hide away from the troubles of life. It is very seldom that one would be invited to a British person's home. It is rude to knock on a person's door if you are not invited. If you are invited, don't ask to see more than the downstairs that your British host invites you into. Never ask how much the house or any of the items in it cost. To the American, most of them want their home to be a place where they can entertain and share their lives with their friends. They may be delighted to give you a full tour of their houses. They may also be pleased when you show your interest and pleasure in their houses. Both British and American people will _ quite a bit of chat and a drink or two before the meal is served. After the first mouthful, you should say how delicious the food is and ask something about it. Remember, never eat with your mouth open and make very little noise while eating. It would be nice of you to help your host in any way. Maybe offer to pour some drinks or clear up after the meal.
Answer: never
[EX A]: British people _ invite friends to their home.

[EX Q]: Article: London--A morning train rides away, across the channel. English kids discuss the Liverpool's football team in a Paris pub. Some Parisians have started to travel to work in London. In the 19th century, Charles Dickens compared the two cities, London and Paris, in A Tale of Two Cities. These days, it might be A tale of One City. As there are few jobs at home over recent years, perhaps 250,000 Frenchmen moved across the channel. With an undersea tunnel, they could travel between cities in three hours. The European Union freed them from immigration and customs. Paris, rich in beauty, is more stylish. But London feels more full of life, and more fun until the pubs shut down. "For me, the difference is that London is real, alive," said Trevor Wheeler, a financial expert. Chantal Jaouen, a professional designer, agrees. "I am French, but I'll stay in London," she said. There is, of course, the other view. Julie Lenoux is a student who moved to London two years ago. "I think people laugh more in Paris," she said. "Both cities have changed _ ," said Larry Collins, an author and sometimes a Londoner. Like most people who know both cities well, he finds the two now fit together comfortably. "I first fell in love with Paris in the 1950s. Things are so much more ordered, and life is better." But certainly not cheaper. In some parts of London, rents can be twice those on Avenue Foch in Paris. Deciding between London and Paris requires a lifestyle choice. Like Daphne Benoit, a French journalism student with perfect English, many young people are happy to be close enough so they don't have to choose. "I love Paris, my little neighborhood, the way I can walk around a centre, but life is too organized," she said. "In London, you can be whoever you want. No one cares."
Answer: Liverpool is a big city in France
[EX A]: It can be inferred that _ .

[EX Q]: Article: Even though orbiters have eyed it from space and landers have rumbled across its surface, Mars still has more secrets to reveal. Two findings emerged this week: the possibility of an active glacier far from the planet's poles and evidence that sulfur--rather than carbon--was the element driving the planet's warmer climate long ago. Both discoveries could force some rethinking about Martian evolution and dynamics--and maybe even provide insights about Earth's past. The glacier discovery was announced Wednesday by the European Space Agency (ESA). A high-resolution stereo camera aboard ESA's Mars Express spacecraft spotted the feature in a region called Deuteronilus Mensae, located in the mid-north latitudes of the planet. The Mars Express science team drew the preliminary conclusion that the material in the feature is water ice and that it accumulated as recently as 10,000 years ago, probably from an underground source. Other deposits of water ice have been mapped at the martian poles, but they're much bigger and are millions of years old. The find is a surprise because the prevailing view is that any water reaching the martian surface from underground quickly evaporates and eventually drifts into space. Yet all of the physical characteristics of the feature are "consistent with that of a glacier," says geologist and team member Ronald Greeley of Arizona State University in prefix = st1 /Tempe. Meanwhile, in the 21 December issue of Science, a team from HarvardUniversityand the Massachusetts Institute of Technology offers a possible solution for the curious absence of carbon-based minerals on Mars. A buildup of carbon dioxide in the ancient martian atmosphere supposedly produced enough of a greenhouse effect to allow liquid water to flow for a time on the surface. The problem is that such a process should have deposited ample carbon-containing minerals on the planet's surface--something that hasn't been found. So the researchers have come up with a new explanation: Large amounts of sulfur dioxide(SO2) in the atmosphere, the result of early volcanic activity, captured enough heat to allow water to flow. This would explain the plentiful distribution of sulfates among martian minerals.
Answer: active glacier
[EX A]:
The main cause of the warm climate on Mars is _ .