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In the dark night of the desert, a group of US Air Force scientists is testing a new device for a missile to target. Designed to seek out the heat of an enemy aircraft engine, it is now going through its paces by tracing the movement of a flashlight waving thirty feet away in the darkness. A hundred yards away, unseen by the man, a rattlesnake sliding between the stones senses a patch of warmth. Although the snake’s mechanism is small enough to be packed into a head the size of a nut, it can detect a change in temperature of one-thousandth of a degree. With a sound the snake closes in and strikes for the kill. Whenever we look in the animal world we find the same story. Almost anything that man can do, nature has already done better. So, it is for the purpose of learning from nature that a new science called bionics has grown up. Its aim is to find out how animal’s instruments work so that man can copy them for his own purpose. Imagine being able to know a friend several miles off by his smell. Male silk moths can do this. Their antennae are so sensitive to the chemical odor of female moths that they can detect their presence by picking up only one molecule of the chemical. Even with their most sensitive instruments, human cannot approach this perfection. Studying beetle’s eyes has already paid off. A group of scientists in Germany found that a beetle can accurately measure with its eyes the speed of moving background. After finding out how a beetle accomplishes this scientists built a machine that operated on the same principle. This instrument is able to determine the ground speed of moving aircraft with a high degree of accuracy. Study of the male silk moth might lead to a new method of ______.
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If you made a list of all the jobs performed by the different kinds of energy, you would fill many pages. Nuclear energy is used in some areas of the United States. But there are dangers. Waste materials from nuclear (51) would destroy life if they leaked (52) the land. When nuclear energy is produced, a lot of (53) is produced, too, so a flow of lake or ocean water is used to cool the operations. Then the water (54) to its source. If the returning water were too hot, it would destroy fish and other (55) . Cow manure is being used to produce a kind of (56) . The manure from farms is put into a machine to convert it to a liquid. Then the gas is formed (57) a natural process. If the converter were not so (58) at the present time, it would be used in many places to provide (59) . Garbage has become an energy source. It (60) to oil, steam, or electricity, or it is used on the land. But recent (61) about power supplies has led to increased interest in the use of wind (62) a source of electrical power. Windmills are clean and they (63) no waste. And they use a (64) resource. Some scientists consider that wind energy systems can fulfill a valuable (65) in meeting the energy needs of industrialized nations and of the developing world.
Women’s minds work differently from men’s. At least, that is what most men are convinced of. Psychologists view the subject either as a matter of frustration or a joke. Now the biologists have moved into this minefield, and some of them have found that there are real differences between the brains of men and women. But being different, they point out hurriedly, is not the same as being better or worse. There is, however, a definite structural variation between the male and female brain. The difference is in a part of the brain that is used in the most complex intellectual processes—the link between the two halves of the brain. The two halves are linked by a trunk line of between 200 and 300 million nerves, the corpus callosum. Scientists have found quite recently that the corpus callosum in women is always larger and probably richer in nerve fibres than it is in men. This is the first time that a structural difference has been found between the brains of women and men and it must have some significance. The question is "What", and, if this difference exists, are there others Research shows that present-day women think differently and behave differently from men. Are some of these differences biological and inborn, a result of evolution We tend to think that is the influence of society that produces these differences. But could we be wrong Research showed that these two halves of the brain had different functions, and that the corpus callosum enabled them to work together. For most people, the left half is used for word-handling, analytical and logical activities ; the right half works on pictures, patterns and forms. We need both halves working together. And the better the connections, the more harmoniously the two halves work. And, according to research findings, women have the better connections. But it isn’t all that easy to explain the actual differences between skills of men and women on this basis. In schools throughout the world girls tend to be better than boys at "language subjects" and boys better at maths and physics. If these differences correspond with the differences in the hemispheric trunk line, there is an unalterable distinction between the sexes. We shan’t know for a while, partly because we don’t know of any precise relationship between abilities in school subjects and the functioning of the two halves of the brain, and we cannot understand how the two halves interact via the corpus callosum. But this striking difference must have some effect and, because the difference is in the parts of the brain involved in intellect, we should be looking for differences in intellectual processing. Brain differences point to superiority of one sex over the other.
People have been painting pictures for at least 30,000 years. The earliest pictures were painted by people who hunted animals. They used to paint pictures of the animals they wanted to catch and kill. Pictures of this kind have been found on the walls of caves in France and Spain. No one knows -why they Were painted there. Perhaps the painters thought that their pictures would help them to catch these animals. Or perhaps human beings have always wanted to tell stories in pictures. About 5000 years ago, the Egyptians and other people in the Near East began to use pictures as kind of writing. They drew simple pictures or signs to represent things and ideas, and also to represent the sounds of their language. The signs there people used became a kind of alphabet. The Egyptians used to record information and to tell stories by putting picture-writing and pictures together. When an important person died, scenes and stories from his life were painted and carved on the walls of the place where he was buried. Some of these pictures are like modem comic strip stories. It has been said that Egypt is the home of the comic strip. But for Egyptians, pictures still had magic power. So they did not try to make their way of writing simple. The ordinary people could not understand it. By the year 1000 BC, people who lived in the area around the Mediterranean Sea had developed a simpler system of writing. The signs they used were very easy to write, and there were fewer of them than in the Egyptian system. This was because each sign, or letter, represented only one sound in their language. The Greeks developed this system and formed the letters of the Greek alphabet. The Romans copied the idea and the Roman alphebet is now used all over the world. These days, we can write down a story, or record information, without using pictures. But we still need pictures of all kinds: drawing, photographs, signs and diagrams. We find them everywhere: in books and newspapers, in the street, and on the wails of the places where we live and work. Pictures help us to understand and remember things more easily, and they can make a story much more interesting. Pictures of animals were painted on the walls of caves in France and Spain because ______.
A. extinctB. bizarreC. interestingD. inactiveE. greedyF. reproduce According to the passage, of all the sea creatures, sea cucumbers are the most ______
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