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.

[Q]: Article: "Is it possible for Brownie not to be glad to be back after a happy stay at my uncle's?"Miss Gauss asked Dad."It'll be all right. Give her a bit more to eat," he said in a low voice, without tearing his eyes from Brownie while his wife was busy packing Brownie's belongings, saying,"Brownie is not so cute as her younger brother, Spotty. Take care of the little thing when walking him." It happened on the night of July 10th, 2013 before the Gausses took a trip to Hawaii. They entrusted their pet to me because they thought I was the first person they'd confide in. And another intention of theirs was that I had already trained Spotty into a wellknown pet in my community, which can act many tricks, such as "Sit down!" "Stand up!" "Give me your right hand!" "Turn around!" She can even sing, and, of course, that's just a strange sharp noise. Having seen them off, I took beautiful Brownie home in my arms, for fear that he would slip away. _ so I tried many ways to be his friend, which made Spotty rather unhappy. They often fought a battle, seemingly to break my roof loose. Soon, Brownie turned out to be an agreeable family member. He was an endearing pet, often begging for comforts in my arms. I seized the chance to train him and he achieved a lot, which I texted Mr.Gauss. They were so overjoyed and decided to fly home ahead of time to see Brownie's qualitative change. But,all this was thoroughly destroyed because of Brownie's death in a traffic accident. What a poor little creature!He was really dogged by bad luck, and he was saved from death shortly after his birth. For whatever reason,therefore, I was overwhelmed by feelings of guilt, which seemed to run most deeply in me. The best way to cheer ourselves up is to try first to cheer somebody else up. That will be an everlasting pain in my heart, a wound that does not heal.
Answer: his owners would go on a trip
[A]: Brownie went to the writer's home mainly because _ .

[Q]: Article: What does the future hold for the problem of housing? A good deal depends, of course, on the meaning of "future". If one is thinking in terms of science fiction and the space age, it is at least possible to assume that man will have solved such trivial and earthly problems as housing. Writers of science fiction, from H.G. Wells onwards, have had little to say on the subject. They have conveyed the suggestion that men will live in great comfort, with every imaginable apparatus to make life smooth, healthy and easy, if not happy. But they have not said what his house will be made of. Perhaps some new building material, as yet unimagined, will have been discovered or invented at least. One may be certain that bricks and mortar(,) will long have gone out of fashion. But the problems of the next generation or two can more readily be imagined. Scientists have already pointed out that unless something is done either to restrict the world's rapid growth in population or to discover and develop new sources of food (or both), millions of people will be dying of starvation or at the best suffering from underfeeding before this century is out. But nobody has yet worked out any plan for housing these growing populations. Admittedly the worst situations will occur in the hottest parts of the world, where housing can be light structure or in backward areas where standards are traditionally low. But even the minimum shelter requires materials of some kind and in the teeming, bulging towns the low-standard "housing" of flattened petrol cans and dirty canvas is far more wasteful of ground space than can be tolerated. Since the war, Hong Kong has suffered the kind of crisis which is likely to arise in many other places during the next generation. Literally millions of refugees arrived to swell the already growing population and emergency steps had to be taken rapidly to prevent squalor and disease and the spread crime. The city is tackling the situation energetically and enormous blocks of tenements are rising at an astonishing aped. But Hong Kong is only one small part of what will certainly become a vast problem and not merely a housing problem, because when population grows at this rate there are accompanying problems of education, transport, hospital services, drainage, water supply and so on. Not every area may give the same resources as Hong Kong to draw upon and the search for quicker and cheaper methods of construction must never stop.
Answer: bricks and mortar will be replaced by some other building material.
[A]: The writer is sure that in the distant future _ .

[Q]: Article: Scientists have exactly discovered the set of brain cells involved in making risky decisions, and have been able to control them in rats using targeted light. By changing the activity of the cells they were able to change the behaviour of risk-taking rats to avoid risk, hinting the approach could in future be used to treat people with impulse control problems. Risk-taking is a key part of survival, knowing when to take a chance could pay off--such as moving to a new area to look for food when pickings are slim. While all animals need an element of risk, the preference towards it varies between individuals. Researchers found this variation, which determines how risk-averse an individual is, is regulated by brain cells in a region of the brain called the nucleus accumbens. This cluster of neurons releases the neurotransmitter dopamine, which regulates the brain's reward and pleasure centres. Previous studies have shown that in patients with Parkinson's disease, taking medication which blocks specific dopamine receptors (DR2) leads to increased gambling behaviour and risk taking behaviour. In studies with rats, researchers were able to use a technique called optogenetics --which uses light sensitive proteins to change the activity of cells--to modify cells with DR2 in the nucleus accumbens. Rats were trained to choose one of two levers, offering them a choice between a "safe" or "risky" choice. The safe option resulted in a small, but consistent amount of a sugar water treat. But the risky choice consistently delivered smaller amounts of sugar water, with the occasional large pay off--essentially encouraging the animals to gamble for a bigger prize. Around two-thirds of the animals weren't keen on risk, opting for the safe option, but the remaining third were risk-seekers. Brain scans of the animals showed that those with low levels of DR2 consistently went for the gamble. But using pulses of light to stimulate the DR2 cells and improve their activity could cause the risk-takers to play it safe and opt for the guaranteed but less rewarding option. Once the light-pulses stopped, the risk-takers returned to their gambling strategy. In the _ , stimulating the same cells had little to no effect. Professor Karl Deisseroth, of Stanford University in California, said: "Humans and rats have similar brain structures involved."And we found a drug known to increase risk preference in people had the same effect on the rats. So every indication is that these findings are relevant to humans. "Risky behavior has its moments where it' s valuable. As a species, we wouldn't have come as far as we have without it."
Answer: dopamine
[A]:
The variation in people's preference towards risks is directly regulated by _ .