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.

Example Input: Article: The place is England. The year is 1928. One of the founding theorists of quantum mechanics , Paul Dirac, is scratching his head because solutions to his equations have  _ unexpected results. For the solutions to make sense, he reasons, there must be a particle that has the mass of an electron but the opposite charge. At the time, such a thing was not known to exist.  Several years pass before American physicist Carl Anderson observes a "positive" electron, or positron that confirms Dirac's prediction.  Antimatter , as the name implies, can be described as the opposite of ordinary matter. Every particle in the universe has characteristics such as mass and charge. With antimatter, the mass remains constant, but the sign of the charge is reversed. All particles have an antimatter counterpart , even the chargeless neutron .  Unlike matter, antimatter is not common. Unless you're in the upper atmosphere, or inside a particle accelerator, you're not going to come across it. "Antimatter was not always so rare," Stephane Coutu, Penn State particle physicist says. There was a time when it was as prevalent as matter itself. "Right after the Big Bang ," Coutu explains, "we believe there must have been exactly the same amounts of matter and antimatter...and yet owing to some small asymmetry in the laws of particle interactions, all of the antimatter and most of the matter in the early universe was annihilated . We are left today with the resulting matter-dominated universe."  Science fiction is rife with tales of high-energy particle annihilation, and indeed, antimatter weapons have appeared in current bestselling novels. This is unrealistic, Coutu says. "[It] would be very impractical owing to very great difficulties in producing and maintaining significant amounts of antimatter."  Technology that uses the properties of antimatter is actually feasible  outside of science fiction, however. Positron emission tomography (PET) is a medical technique that can be used to detect cancer, measure blood flow and detect coronary artery disease. While antimatter may never be used as a bomb, it certainly has a positive future in life-saving medical diagnostic tools, the anti-weapon. 
 Answer: It's not easy to produce and maintain large quantities of antimatter
Example Output: According to Coutu,   _  .

Example Input: Article: Have you ever imagined what the world will be in the near future? A recent study shows that the world in 2100 will be more crowded, more polluted and less stable ecologically than the world we live in now. Visible ahead is serious stress involving population, resource and environment. Despite greater food output, people in the world will be poorer in many ways than they are today.     For hundred of millions of the extremely poor, the outlook for food and other necessities of life will be no better, for many it will be worse. While the economies of the developing countries are expected to grow at a faster rate than those of the industrialized nation, the total national product per head in most less developed countries remains low. The existing gap between the rich and poor nations will further widen. World food production is estimated to increase by 90 percent from 2000 to 2100. Most of that increase goes to the countries that already have   higher per-head food consumption. Meanwhile, per-head consumption of food in the developing countries will scarcely  improve or will actually fall far below the present inadequate level. What is worse is that prices for food are expected to double. As a result, many less developed countries will have increasing difficulties meeting energy needs. For the one quarter of mankind that depends primarily on wood for fuel, the outlook is not hopeful. Regional water shortage will become more sever. In the 1970-2100 period population growth will require twice as much water as it does today in nearly half the world. Still greater increases would be needed to improve standards of living. Development of new water supply will become more costly. 
 Answer: the living standard of the world's population will improve greatly
Example Output: According to the passage, in 2100 while output of food will be greater,   _  .

Example Input: Article: The ancient Egyptians appeared to be among the first early civilizations to learn how to grow roses. In 1888, at Hawara in the El Faiyum area of Egypt, two-thousand-year-old roses were found in ancient tombs. The discovery suggested roses were an important part of the complex burial ceremony which took place when an important person died. The roses found in the tombs are thought by modern experts to be the oldest preserved flowers ever found in the world. They must have been cut and dried before flowering so that they would remain undamaged. Over the centuries, the roses had shrunk and became tight balls, but on careful examination it was discovered that the petals   themselves were hardly damaged.  Egypt's skill in mass-cultivation of roses in early times led to the flowers becoming an important export product. At the height of the Roman Empire, Egypt exported large quantities of roses to the Roman courts. Wealthy Romans loved the beautiful color1s and sweet smells of roses. So the Romans attempted to grow their own roses and they eventually mastered the art of mass cultivation. Egypt then decided to concentrate on growing grain instead of roses, so grain soon took over as the number-one agricultural product of Egypt.  Roses were appreciated in other early civilizations too, including Greece and Persia. They are a decorative feature on coins, sculpture, and vases dating back thousands of years. There is also evidence that roses were highly valued by the Chinese who believed that the flowers could be used to help treat a wide range of illnesses, from toothache to skin and chest diseases.  In the modern world, the rose has not lost its popularity as the "Queen of Flowers" -- the name given to it by the Greek poetess Sappho. Even today more roses are sold than any other flower. Modern techniques have enabled people to create ever more beautiful roses. Transportation by air makes it possible to grow roses in countries with favorable climates and sell them within twenty-four hours in profitable markets all over the world. Tons of roses are transported this way every week. Roses from Ecuador, a country in northern South America, can be bought in Holland, even though that country itself has a huge rose-growing business. 
 Answer: finely preserved
Example Output:
The roses discovered at Hawara in 1888 were   _  .

