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In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.
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Article: Below is a selection from a popular science book. If blood is red, why are veins blue? Actually, veins are not blue at all. They are more of a clear, yellowish colour. Although blood looks red when it's outside the body, when it's sitting in a vein near the surface of the skin, it's more of a dark reddish purple colour. At the right depth, these blood-filled veins reflect less red light than the surrounding skin, making them look blue by comparison. Which works harder, your heart or your brain? This question depends on whether you're busy thinking or busy exercising. Your heart works up to three times harder during exercise, and shifts enough blood over a lifetime to fill a supertanker. But, in the long run, your brain probably tips it, because even when you're sitting still your brain is using twice as much energy as your heart, and it takes four to five times as much blood to feed it. Do old people shrink as they age? Yes and no. Many people do get shorter as they age. But, when they do, it isn't because they're shrinking all over. They simply lose height as their spine becomes shorter and more curved due to disuse and the effects of gravity . Many (but not all) men and women do lose height as they get older. Men lose an average of 3-4 cm in height as they age, while women may lose 5 cm or more. If you live to be 200 years old, would you keep shrinking till you were, like 60 cm tall, like a little boy again?No, because old people don't really shrink!It is not that they are growing backwards--their legs, arms and backbones getting shorter. When they do get shorter, it's because the spine has shortened a little. Or, more often, become more bent and curved. Why does spinning make you dizzy ? Because your brain gets confused between what you're seeing and what you're feeling. The brain senses that you're spinning using special gravity and motion sensing organs in your inner ear, which work together with your eyes to keep your vision and balance stable. But when you suddenly stop spinning , the system goes out of control, and your brain thinks you're moving while you're not! Where do feelings and emotions come from? Mostly from an ancient part of the brain called the limbic system. All mammals have this brain area--from mice to dogs, cats, and humans. So all mammals feel basic emotions like fear, pain and pleasure. But since human feelings also involve other newer bits of the brain, we feel more complex emotions than any other animal on the planet.
Answer: Dark reddish purple.
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What is the colour of blood in a vein near the surface of the skin?

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Article: It's hard to avoid looking like a fool on April Fool's Day. On April 1 each year, people play tricks on each other. These tricks are usually silly rather than mean. Classmates sometimes tie each other's shoelaces to their chairs.Teachers might hand out an impossibly difficult surprise test that scares students before they realize it's only a joke. Newspapers announce fake contests (such as "Win an elephant!") and report on fake stories (like "UFO" lands in New York City). Forget gifts, songs and special foods--those are for the other holidays of the year. On April Fool's Day, the only tradition is to laugh (and maybe to cause a little bit of trouble). One April Fool's Day, when I was in high school, a group of students in my class played a very clever and funny trick on the teachers. They bought some chickens and set them free in our school cafeteria. The chickens ran all round the school, in and out of classrooms and under our feet. Feathers were flying everywhere. Teachers began running after the chickens, trying to catch them. Finally, they caught four of them. But the chickens were wearing numbered tags around their necks, and the teachers discovered that they had only caught chickens No.1, 2, 3, and 5.Where was chicken No.4? The teachers looked and looked. They couldn't find another chicken. After a few hours, they realized that the students had played another joke on them: There were only four chickens in the first place! They've been tricked by the numbers on the chickens. It's been a long time since I was in high school, but that April Fool's Day remains one of my favorite memories from those years.
Answer: They wanted to play a trick on teachers.
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Why did students set chickens free?

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Article: The Nobel Prizes in physiology or medicine, physics and chemistry are the most respected prizes in science. But talk to scientists in private, and many will complain why (besides jealousy, perhaps) are some scientists unhappy with the Nobels? One reason is that the committees can often be slow to recognize achievement. Alfred Nobel specified in his will that the prizes should reward work done in the previous year. But experience soon showed that this was risky, as medals were given out for discoveries that later proved questionable. So a degree of caution is probably advisable. Sometimes, though, it can lead to strange results. Subrahmanyan Chandrasekhar, for instance, had to wait until 1983 to win a prize for work he had done in the 1930s on the structure of stars. However, Albert Einstein never won a prize for his theory of relativity. Even though some pretty suggestive evidence had been produced by Arthur Eddington in 1919, relativity, which has later passed every experimental test ever thrown at it, was still considered somewhat risky and obscure. Another criticism concerns the tradition that no more than three people can share a prize. Science is rarely this clear-cut. Take this year's physics prize, which recognised Peter Higgs for predicting the existence of the mass-bestowing particle that now bears his name. Dr Higgs was only one of several people with a claim. Two other teams---- Rober Brout and Francois Englert, as well as Gerald Guralnik, Carl Hageh and Tom Kibble----- submitted papers on the same idea to the same journal that published Dr Higgs's work, all within a few months of each other. Science often works like this, with different people coming up with similar ideas at similar times. In the event, the committee decided to honour Dr Engler (Brout is dead, therefore unqualified), whose paper was earlier than Dr Higgs's but did not explicitly predict a particle, over Dr Guralnik and his collaborators, who were more comprehensive but published a few weeks later.
Answer: because the Nobles are quite possibly slow to recognize achievement
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According to the passage why some of the scientists are unhappy with the Nobels?