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 Input:
Article: . As the world's largest terrestrial carnivore ,the polar bear is the king of the great white north. Adult males can measure more than 9 feet in length and weigh between 770 and 1,430 pounds. The bear's body and neck are elongated, and the head is narrow and long with small, rounded ears. Polar bear populations can be found in northern Canada, Greenland, Norway and Russia, and there have been reports that polar bear tracks have been found as far north as the North Pole. The 5,000,000-square-mile range of the polar bear circles the Arctic and contains stretches of open water where seals are easily caught. Polar bears live on the annual Arctic sea ice that provides a platform from which they can hunt. They hunt seals on the sea ice by breaking into seal dens in the sea ice. The dens aren't visible from above,but seeing is less important than smelling to a polar bear -- with their keen sense of smell,polar bears can sense the breathing holes of seals in their dens beneath the snow and ice. As the southern edge of the Arctic ice cap melts in summer, polar bears are stranded on land and spend their summers fasting ,living off body fat stored from hunting in spring and winter. It might come as a surprise that this species faces an uncertain future. Climate change is causing the disappearance of sea ice from which polar bears hunt seals. Sea ice in the Arctic is melting earlier and forming later each year. With about 22,000 polar bears living in the wild,the species is not endangered at the moment, but its future is far from certain. People have reached an agreement that controls the hunting of polar bears and directs each nation to protect their habitats, but it does not protect the bears against the biggest man-made threat to their survival : global warming. If current warming trends continue, scientists believe that polar bears may disappear within 100 years.
Answer: necks

Ex Output:
Polar bears search for seals mainly through their _ .

Ex Input:
Article: Eating too much fatty food, exercising too little and smoking can raise your future risk of heart disease. But there is another factor that can cause your heart problems more immediately: the air you breathe. Previous studies have linked high exposure to environmental pollution to an increased risk of heart problem, but two analyses now show that poor air quality can lead to heart attack or stroke within as little as a few hours after exposure. In one review of the research, scientists found that people exposed to high levels of pollutants were up to 5% more likely to suffer a heart attack within days of exposure than those with lower exposure. A separate study of stroke patients showed that even air that the U. S. Environmental Protection Agency (EPA) considers to be of "moderate" quality and relatively safe for our health can raise the risk of stroke as much as 34% within 12 to 14 hours of exposure. The authors of both studies stress that these risks are relatively small for healthy people and certainly modest compared with other risk factors such as smoking and high blood pressure. However, it is important to be aware of these dangers because everyone is exposed to air pollution regardless of lifestyle choices. So stricter regulation by the EPA of pollutants may not only improve environmental air quality but could also become necessary to protect public health.
Answer: heart problems and air quality

Ex Output:
The text mainly discusses the relationship between _ .

Ex Input:
Article: Millions of people are using cell phones today.In many places it is actually considered unusual not to use one.In many countries,cell phones are very popular with young people.They find that the phones are more than a means of communication--having a mobile phone shows that they are cool and connected. The explosions around the world in mobile phone use make some health professional worried.Some doctors are concerned that in the future many people may suffer health problems from the use of mobile phones.In England,there has been a serious debate about this issue.Mobile phone companies are worried about the negative publicity of such ideas.They say that there is no proof that mobile phones are bad for your health. On the other hand,why do some medical studies show changes in the brain cells of some people who use mobile phones?Signs of change in the issues of the brain and head can be _ with modern scanning equipment.In one case,a traveling salesman had to retire at a young age because of serious memory loss.He couldn't remember even simple tasks.He would often forget the name of his own son.This man used to talk on his mobile phone for about six hours a day,every day of his working week,for a couple of years.His family doctor blamed his mobile phone use,but his employer's doctor didn't agree. What is it that makes mobile phones potentially harmful?The answer is radiation.Hightech machines can detect very small amounts of radiation from mobile phones.Mobile phone companies agree that there is some radiation.But they say the amount is too small to worry about. As the discussion about their safety continues,it appears that it's best to use mobile phones less often.Use your regular phone if you want to talk for a long time.Use your mobile phone only when you really need it.Mobile phones can be very useful and convenient,especially in emergencies.In the future,mobile phones may have a warning label that says they are bad for your health.So for now,it's wise not to use your mobile phone too often.
Answer: they're cheap

Ex Output:
People buy cell phones for the following reasons except that _ .