判断题The American Character The American is wonderfully alive; and his vitality, not having often found a suitable outlet, makes him appear agitated on the surface; he is always letting of an unnecessarily loud blast of incidental steam. Yet his vitality is not superficial; it is inwardly prompted, and as sensitive and quick as a magnetic needle. He is inquisitive, and ready with an answer to any question that he may put to himself of his own accord; but if you try to pour instruction into him, on matters that do not touch his own spontaneous life, he shows the most extraordinary powers of resistance and forgetfulness; so that he often is remarkably expert in some directions and surprisingly slow in others. He seems to bear lightly the sorrowful burden of human knowledge. In a word, he is young. What sense is there in this feeling, which we all have that the American is young? His country is blessed with as many elderly people as any other, and his descent from Adam, or form the Darwinian rival of Adam, cannot be shorter than that of his European cousins. Nor are his ideas always very fresh. Old conventions and rigid bits of morality and religion, with much seemly and antique political understanding, remain clear-cut in him, as in the mind of a child; he may carry all this about with an unquestioning familiarity which does not comport understanding. To keep traditional sentiments in this way untouched and uncriticised is itself a sign of youth. A good young man is naturally conservative and loyal on all those subjects which his experience has not brought to a test; advanced opinions on politics, marriage, or literature are comparatively rare in America; they are left for the ladies to discuss, and usually to condemn, while the men get on with their worked. In spite of what is 01d fashioned in his more general ideas, the American is unmistakably young; and this, I should say, for two reasons: one, that he is chiefly occupied with his immediate environment, and the other, that his reactions upon it are inwardly prompted, spontaneous, and full of vivacity and self-trust. His views are not yet lengthened; his will is not yet broken or transformed. The present moment, however in this, as in other things, may mark a great change in him; he is perhaps now reaching his majority, and all I say may hardly apply today, and may not apply at all tomorrow. I speak of him as I have known him; and whatever moral strength may occur to him later, I am not sorry to have known him in his youth. The charm of youth, even when it is a little boisterous, obvious obedience to that pure, seminal principle which, having formed the body and its organs, always directs their movement, unless it is forced by vice or necessity to make them crooked, or remains young, and, wherever it is able to break through, sprouts into something green and tender. We are all as young at heart as the most youthful American, but the seed in his case has fallen upon virgin soil, where it may spring up more bravely and with less respect for the giants of the wood. People seem older when their perennial natural youth is encumbered with more possessions and prepossessions, and they are mindful of the many things they have lost or missed. The American is not mindful to them.

判断题Computers can always be viewed as hierarchical ordered systems that can be broken down into simpler component parts in order to fully understand their operation.

判断题Minicomputers and microcomputers have a similar memory capacity.

判断题Cookies, to a degree

判断题4．A PC can be a laptop or a desktop.

判断题It is necessary that those computer-controlled motors to generate force feedback be made as small as possible because they have to be put on the users body.

判断题All inspection bodies are govemmental.

判断题2．With advanced techniques

判断题With the two advances in computer technology

判断题People havent developed a lot on computer languages in the past five years.

判断题Memory-to-memory architecture supports the pipelined flow of vector operands directly from pipelines to the memory and then from the memory back to the pipelines.

判断题Both centralized systems and distributed systems need the same software.

判断题The processors in a multiprocessor system communicate with each other through shared variable in a common memory.

判断题Truck bill of lading is a non-negotiable document of title stating the point of origin, destination , consignee , and other pertinent information.

判断题The Letter of credit shall be examined only by the exporter.

判断题Copying Birds May Save Aircraft Fuel Both Boeing and Airbus have trumpeted the efficiency of their newest aircraft, the 787 and A350 respectively. Their clever designs and lightweight composites certainly make a difference. But a group of researchers at Stanford University, led by Ilan Kroo, has suggested that airlines could take a more naturalistic approach to cutting jet-fuel use, and it would not require them to buy new aircraft. The answer, says Dr. Kroo, lies with birds. Since 1914, scientists have known that birds flying in formation—a V-shape—expend less energy. The air flowing over a bird"s wings curls upwards behind the wingtips, a phenomenon known as upwash. Other birds flying in the upwash experience reduced drag, and spend less energy propelling themselves. Peter Lissaman, an aeronautics expert who was formerly at Caltech and the University of Southern California, has suggested that a formation of 25 birds might enjoy a range increase of 71%. When applied to aircraft, the principles are not substantially different. Dr. Kroo and his team modeled what would happen if three passenger jets departing from Los Angeles, San Francisco and Las Vegas were to assemble over Utah, assume an inverted V formation, occasionally change places so all could have a turn in the most favourable positions, and proceed to London. They found that the aircraft consumed as much as 15% less fuel (coupled with a reduction in carbon-dioxide output). Nitrogen-oxide emissions during the cruising portions of the flight fell by around a quarter. There are, of course, knots to be worked out. One consideration is safety, or at least the perception of it. Would passengers feel comfortable traveling in companion? Dr. Kroo points out that the aircraft could be separated by several nautical miles, and would not be in the intimate groupings favoured by display teams like the Red Arrows. A passenger peering out of the window might not even see the other planes. Whether the separation distances involved would satisfy air traffic-control regulations is another matter, although a working group at the International Civil Aviation Organisation has included the possibility of formation flying in a blueprint for new operational guidelines. It remains to be seen how weather conditions affect the air flows that make formation flight more efficient. In zones of increased turbulence, the planes" wakes will decay more quickly and the effect will diminish. Dr. Kroo says this is one of the areas his team will investigate further. It might also be hard for airlines to co-ordinate the departure times and destinations of passenger aircraft in a way that would allow them to gain from formation flight. Cargo aircraft, in contrast, might be easier to reschedule, as might routine military flights. As it happens, America"s armed forces are on the case already. Earlier this year the country"s Defence Advanced Research Projects Agency announced plans to pay Boeing to investigate formation flight, though the programme has yet to begin. There are reports that some military aircraft flew in formation when they were low on fuel during the Second World War, but Dr. Lissaman says they are unsubstantiated. "My father was an RAF pilot and my cousin, the skipper of a Lancaster, lost over Berlin," he adds. So he should know.

判断题There are two levels of web portals identified in the passage: information and communication.

判断题If a buyer accepts any part of an indivisible unit of goods, he is considered to have accepted the whole unit.

判断题According to Uniform Customs and Practice for Documentary Credits, about should be interpreted as not exceeding 5/% of the total quantity.