单选题If you can't afford to travel, reading guidebooks can give you a (n) ______experience of traveling in foreign countries.

单选题How fast is your personal computer? When people ask this question, they are typically referring to the frequency of a minuscule clock inside the computer, a crystal oscillator that sets the basic rhythm used throughout the machine. In a computer with a speed of one gigahertz, for example, the crystal "ticks" a billion times a second. Every action of the computer takes place in tiny steps, each a billionth of a second long. A simple transfer of data may take only one step; complex calculations may take many steps. All operations, however, must begin and end according to the clock's timing signals. Because most modern computers use a single rhythm, we call them synchronous. Inside the computer's microprocessor chip, a clock distribution system delivers the timing signals from the crystal oscillator to the various circuits, just as sound in air delivers the beat of a drum to soldiers to set their marching pace. Because all parts of the chip share the same rhythm, the output of any circuit from one step can serve as the input to any other circuit for the next step. The synchronization provided by the clock helps chip designers plan sequences of actions for the computer. The use of a central clock also creates problems. As speeds have increased, distributing the timing signals has become more and more difficult. Present day keeping the rhythm identical in all parts of a large chip requires careful design and a great deal of electrical power. Wouldn't it be nice to have an alternative? Our research group at Sun Microsystems Laboratories seeks such alternatives. Along with several other groups worldwide, we are investigating ways to design computing systems in which each part can proceed at its own pace instead of depending on the rhythm of a central clock. We call such systems asynchronous. Each part of an asynchronous system may extend or shorten the timing of its steps when walking across rough terrain.

单选题Computer programmers often remark that computing machines, with a perfect lack of discrimination, will do any foolish thing they are told to do. The reason for this lies, of course, in the narrow fixation of the computing machine"s "intelligence" on the details of its own perceptions—its inability to be guided by any large context. In a psychological description of the computer intelligence, three related adjectives come to mind: single-minded, literal-minded, and simple-minded. Recognizing this, we should at the same time recognize that this single-mindedness, literal-mindedness, and simplemindedness also characterizes theoretical mathematics, though to a lesser extent. Since science tries to deal with reality, even the most precise sciences normally work with more or less imperfectly understood approximations toward which scientists must maintain an appropriate skepticism. Thus, for instance, it may come as a shock to mathematicians to learn that the Schrodinger equation (薛定谔方程) for the hydrogen atom is not a literally correct description of this atom, but only an approximation to a somewhat more correct equation taking account of spin, magnetic dipole, and relativistic effects; and that this corrected equation is itself only an imperfect approximation to an infinite set of quantum field, theoretical equations. Physicists, looking at the original Schrodinger equation, learn to sense in it the presence of many invisible terms in addition to the differential terms visible, and this sense inspires an entirely appropriate disregard for the purely technical features of the equation. This very healthy skepticism is foreign to the mathematical approach. Mathematics must deal with well-defined situations. Thus, mathematicians depend on an intellectual effort outside of mathematics for the crucial specification of the approximation that mathematics is to take literally. Give mathematicians a situation that is the least bit ill-defined, and they will make it well-defined, perhaps appropriately, but perhaps inappropriately. In some cases, the mathematicians" literal-mindedness may have unfortunate consequences. The mathematicians turn the scientists" theoretical assumptions, that is, their convenient points of analytical emphasis, into axioms, and then take these axioms literally. This brings the danger that they may also persuade the scientists to take these axioms literally. The question, central to the scientific investigation but intensely disturbing in the mathematical context—what happens if the axioms are relaxed? —is thereby ignored. The physicist rightly dreads precise argument, since an argument that is convincing only if it is precise loses all its force if the assumptions on which it is based are slightly changed, whereas an argument that is convincing though imprecise may well be stable under small perturbations of its underlying assumptions.

单选题Even though he was guilty, the______judge did not send him to prison.

单选题The ______ of a cultural phenomenon is usually a logical consequence of some physical aspects in the life style of the people.

单选题Coca-cola has overcome Pepsi"s ______ edge in Eastern Europe.

单选题Seeing the closet on fire, he made a futile attempt to save the paintings from the flames. The underlined word probably means______.

单选题Johnson______the problem in his mind for two more days before he came to a conclusion.

单选题David tends to feel useless and unwanted in a society that gives so much ______ to those who compete well.

单选题The phenomenon of stress has been widely discussed and referred to as one of the central problems of our age. Globalization and the improved technology it brings only seems to make this problem worse, creating more options while at the same time making our lives more complex. Closely bound up with stress is the problem of "time famine". In Britain, for example, the combination of the longest working hours in Europe and the highest proportion of working women in Europe means people have less and less time to themselves. Add to this the rise in the number of single-person households and the work ethic promoted by successive governments since the early eighties and it becomes easy to see why time is now at a premium for so many of us. One response to this has come from the USA, so often the forerunner in what is fashionable, in the form of lifestyle management. This involves hiring a company to repair the house, do the shopping and a host of other time consuming tasks. Some analysts insist that the management of people"s time could be big business in the next 10 years. In the USA lifestyle management companies have been around for a while but now it seems that the British are keen to use them too. What most potential customers want is quality time. This means taking away the day to day hassles connected with running our lives. Whereas in the past there always seemed to be time for arranging private lives and keeping up with everyday demands of house, health, children or holidays, nowadays the work obsessed population, tied to the office, do not appear to be able to cope with such inconveniences. In other words, people require a separate Personal Assistant for their lifestyle! The jury is out, however, as to whether this new service is beneficial or not. Being constantly pressed for time is undoubtedly stressful and what could be better than relieving such pressures by offloading some of our more mundane tasks on a willing helper? Perhaps this can also be a way to ensure that you get quality service:. It is often said that a large part of Britain"s service sector aims purely and simply at short term profit in return for bad quality goods and poor service. If you put experts in charge of finding a good plumber at a reasonable rate you can at least be assured that your leaking pipes will be fixed properly. This raises an important question, however. Is it really good for us to create more time to spend at work when we are already exhausted from working long hours? It may be far more important to take control of our private lives ourselves and in so doing relieve stress by giving ourselves a proper escape from the cares of the work-place. After all, if you do not have time to look after your own home and to organize your own life, then, just maybe, you have got your priorities wrong. There may be one reason why, in the end, the lifestyle management business will not take off in the UK and that is the inherendy conservative nature of the British. To really embrace this new concept we might all need to rethink our lives!

单选题Being impatient is______with being a good teacher.

单选题The decision of our company was that we ______everything prepared well by the end of this month.

单选题These pictures will show you ______.

单选题Younger mothers may feel like the coolest room at nursery school, or they may feel______ from her unencumbered college pals.

单选题Passage Four The other day an acquaintance of mine, a gregarious and charming man, told me he had found himself unexpectedly alone in New York for an hour or two between appointments. He went to the Whitney and spent the "empty" time looking at things in solitary bliss. For him it proved to be a shock nearly as great as falling in love to discover that he could enjoy himself so much alone. What had he been afraid of, I asked myself? That, suddenly alone, he would discover that he bored himself, or that there was, quite simply, no self there to meet? But having taken the plunge, he is now on the brink of adventure ; he is about to be launched into his own inner space, space as immense, unexplored, and sometimes frightening as outer space to the astronaut. His every perception will come to him with a new freshness and, for a time, seem startlingly original. For anyone who can see things for himself with a naked eye becomes, for a moment or two, something of a genius. With another human being present vision becomes double vision, inevitably. We are busy wondering, what does my companion see or think of this, and what do I think of it? The original impact gets lost, or diffused. "Music I heard with you was more than music. " Exactly and therefore music itself can only be heard alone Solitude is the salt of personhood. It brings out the authentic flavor of every experience. "Alone one is never lonely: the spirit adventures, walking in a quiet garden, in a cool house, abiding single there. " Loneliness is most acutely felt with other people, for with others, even with a lover sometimes, we suffer from our differences of taste, temperament, mood Human intercourse often demands that we soften the edge of perception, or withdraw at the very instant of personal truth for fear of hurting, or of being inappropriately present, which is to say naked, in a social situation. Alone we can afford to be wholly whatever we are, and to feel whatever we feel absolutely. That is a great luxury! For me the most interesting thing about a solitary life, and mine has been that for the last twenty years, is that it becomes increasingly rewarding. When I can wake up and watch the sun rise over the ocean, as I do most days, and know that I have an entire day ahead, uninterrupted, in which to write a few pages, take a walk with my dog, lie down in the afternoon for a long think (why does one think better in a horizontal position?), read and listen to music, I am flooded with happiness. I am lonely only when I am overtired, when I have worked too long without a break, when for the time being I feel empty and need filling up. And I am lonely sometimes when I come back home after a lecture trip, when I have seen a lot of people and talked alot, and am full to the brim with experience that needs to be sorted out. Then for a little while the house feels huge and empty, and I wonder where my selfish hiding. It has to be recaptured slowly by watering the plants, perhaps, and looking again at each one as though it were a person, by feeding the two cats, by cooking a meal. It takes a while, as I watch the surf blowing up in fountains at the end of the field, hut the moment comes when the world falls away, and the self emerges again from the deep unconscious, bringing back all I have recently experienced to be explored and slowly understood, when I can converse again with my hidden powers, and so grow, and so be renewed, till death do us part.

单选题A good English learner is supposed to ______a large vocabulary.

单选题That our family environment has much to do with our abilities, characters and behavior ______central to his theory.

单选题The police have caught that ______ man who carried off the pure girl, tying her to the railway line.

单选题In the art of the Middle Ages, we never encounter the personality of the artist as an individual; rather it is diffused through the artistic genius of centuries embodied in the rifles of religious art. Art of the Middle Ages is first a sacred script, the symbols and meanings of which were well settled. The circular halo placed vertically behind the head signifies sainthood, while the halo impressed with a cross signifies divinity. By bare feet, we recognize God, the angels, Jesus Christ and the apostles, but for an artist to have the Virgin Mary depicted with bare feet would have been tantamount to heresy. Several concentric, wavy lines represent the sky, while parallel lines water or the sea. A tree which is to say a single stalk with two or three stylized leaves informs us that the scene is laid on earth. A tower with a window indicates a village, and, should an angel be watching from depicted with curly hair, a short beard, and a tonsure, while Saint Paul has always a bald head and a long beard. A second characteristic of this iconography is obedience to a sacred mathematics. "The Divine Wisdom", wrote Saint Augustine, "reveals itself everywhere in numbers", a doctrine attributable to the Neo-Platonists who revived the genius of Pythagoras. Twelve is the master number of the Church and is the product of three, the number of the Trinity, and four, the number of material elements. The number seven, the most mysterious of all numbers, is the sum of four and three. There are the seven ages of man, seven virtues, and seven planets; in the final analysis, the seven-tone scale of Gregorian music is the sensible embodiment of the order of the universe. Numbers require also symmetry. At Charters, a stained glass window show the four prophets, Isaac, Eekiel, Danniel, and Jerimiah, carrying on their shoulders the four evangelists, Matthew, Mark, Luke and John. A third characteristic of art is to be a symbolic language, showing us one thing and inviting us to see another. In this respect, the artist was called upon to imitate God, who had hidden a profound meaning behind the literal and wished itself to be a moral lesson to man. Thus, every painting is an allegory. In a scene of the final judgment, we can see the foolish virgins at the left hand of Jesus and the wise at his right hand, and we understand that this symbolizes those who are lost and those who are saved. Even seemingly insignificant details carry hidden meaning: The lion in a stained glass window is the figure of the Resurrection. These, then, are the definite characteristics of art of the Middle Ages, a system within which even the most mediocre talent was elevated by the genius of the centuries. The artists of the early renaissance broke with tradition at their own peril. When they are not outstanding, they are scarcely able to avoid insignificant and banality in their religious works, and even when they are great, they"re no more than the equals of the old masters who passively followed the sacred rules.

单选题The captain ______ the horizon for approaching ships.