Through a series of experiments an American scientist has gained an understanding of the social structure of the most complex of ant societies. The ants examined are the only creatures other than man to have given up hunting and collecting for a completely agricultural way of life. In their underground nests they cultivate gardens on soil made from finely chopped leaves. This is a complex operation requiring considerable division of labour. The workers of this type of ants can be divided into four groups according to the size. Each of the groups performs a particular set of jobs.               The making and care of the gardens and the nursing of the young ants are done by the smallest workers. Slightly larger workers are responsible for chopping up leaves to make them suitable for use in the gardens and for cleaning the nest. A third group of still larger ants do the construction work and collect fresh leaves from outside the nest. The largest are the soldier ants, responsible for defending the nest.               To find out how good the various size-groups are at different tasks, the scientist measured the amount of work done by the ants against the amount of energy they used. He examined first the gathering and carrying of leaves. He selected one of the size-groups, and then measured how efficiently these ants could find leaves and run back to the nest. Then he repeated the experiment for each of the other size-groups. In this way he could see whether any group could do the job more efficiently than the group normally undertaking it.               The intermediate-sized ants that normally perform this task proved to be the most efficient for their energy costs, but when the scientist examined the whole set of jobs performed by each group of ants it appeared that some sizes of worker ant were not ideally suited to the particular jobs they performed. The organization of the ants has the effect of   _  . A) getting the most work done B) dividing the work up systematically C) each ant helping with all the tasks D) each ant doing what it can do best
B
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The vitamins necessary for a healthy body are normally supplied by a good mixed diet, including a variety of fruits and green vegetables. It is only when people try to live on a very _ diet, say that when trying to lose weight, that it is necessary to make special provisions to supply the missing vitamins. An example of the dangers of a restricted diet may be seen in the disease known as "beri-beri", which used to make large numbers of Eastern people who lived mainly on rice suffer. In the early years of last century, a Dutch scientist named Eijkman was trying to discover the cause of beri-beri. At first he thought it was transmitted by a germ   . He was working in a Japanese hospital, where the patients were fed on polished rice which had had the outer coverings removed from the grain, it was thought this would be easier for weak and sick people to digest. Eijkman thought his germ theory was proved when he noticed the chickens in the hospital yard, which were fed on remains from the patients' plates, were also showing signs of the disease. He then tried to separate the germ, which he thought was causing the disease, but his experiments were interrupted by a hospital official, who ordered that the rice without coverings, even though left over by the patients, was too good for chickens. It should be recooked for the patients, and the chickens should be fed on cheap, rough rice with the outer coverings still on the grain. Eijkman noticed that the chickens began to recover on the new diet. He began to consider the possibility that eating unmilled rice   somehow prevented or cured beri-beri--even that a lack of some ingredient   in the coverings may be the cause of the disease. Indeed this was the case. The element needed to prevent beri-beri was shortly afterwards separated from rice coverings and is now known as vitamin B. The milled rice, though more expensive, was in fact causing the disease the hospital was trying to cure. Nowadays, this terrible disease is much less common thanks to our knowledge of vitamins. What do we know about the disease beri-beri? A) It killed large numbers of people. B) It resulted from lack of vitamins. C) It was transmitted by milled rice. D) It was caused by diseased chickens.
B
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Napoleon, as a character in Tolstoy's War and Peace, is more than once described as having "fat little hands". Nor does he "sit well or firmly on the horse". He is said to be "undersized", with "short legs" and a "round stomach". The issue here is not the accuracy of Tolstoy's description-it seems not that far off from historical accounts but his choice of facts: other things that could be said of the man are not said. We are meant to understand the difference of a warring commander in the body of a fat little Frenchman. Tolstoy's Napoleon could be any man wandering in the streets and putting a little of powdered tobacco up his nose-and that is the point. It is a way the novelist uses to show the moral nature of a character. And it turns out that, as Tolstoy has it, Napoleon is a crazy man. In a scene in Book Three of War and Peace, the wars having reached the critical year of 1812,Napoleon receives a representative from the Tsar   ,who has come with peace terms. Napoleon is very angry: doesn't he have more army? He, not the Tsar, is the one to make the terms. He will destroy all of Europe if his army is stopped. "That is what you will have gained by engaging me in the war!" he shouts. And then, Tolstoy writes, Napoleon "walked silently several times up and down the room, his fat shoulders moving quickly". Still later, after reviewing his army amid cheering crowds, Napoleon invites the shaken Russian to dinner. "He raised his hand to the Russian's face," Tolstoy writes, and "taking him by the ear pulled it gently. . . ". To have one's ear pulled by the Emperor was considered the greatest honor and mark of favor at the French court. "Well, well, why don't you say anything?" said he, as if it was ridiculous in his presence to respect any one but himself, Napoleon. Tolstoy did his research, but the composition is his own. Tolstoy intended to present Napoleon as a man who is  _  . A) ill-mannered in dealing with foreign guests B) fond of showing off his iron will C) determined in destroying all of Europe D) crazy for power and respect
D
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In early autumn I applied for admission to college. I wanted to go nowhere but to Cornell University, but my mother fought strongly against it. When she saw me studying a photograph of my father on the sports ground of Cornell, she tore it up. "You can't say it's not a great university, just because Papa went there." "That's not it at all. And it is a top university." She was still holding the pieces in her hand. "But we can't afford to send you to college." "I wouldn't dream of asking you for money. Do you want me to get a job to help support you and Papa? Things aren't that bad, are they?" "No," she said. "I don't expect you to help support us." Father borrowed money form his rich cousins to start a small jewellery shop, His chief customers were his old college friends. To get new customers, my mother had to help. She picked up a long-forgotten membership in the local league of women, so that she could get to know more people. Whether those people would turn into customers was another question. I knew that my Parents had to wait for quite a long time before their small investment   could show returns. What's more, they had not wanted enough to be rich and successful ;Otherwise they could not possibly have managed their lives so badly. I was torn between the desire to help them and change their lives, and the determination not to repeat their mistakes. I had a strong belief in my power to go what I wanted. After months of hard study I won a full college scholarship .My father could hardly contain his pride in me, and my mother eventually gave in before my success. The father started his small shop with the money from  _  . A) a local league B) his university C) his relatives D) his college friends

C
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