【正文】 eatest importance, because they also contributing to defining him as man and permit him to pursue a life increasingly more truly human. But even while enjoying the results of technical progress, he must defend the primacy and autonomy of pure knowledge. Knowledge sought directly for its practical applications will have immediate and foreseeable success, but not the kind of important result whose revolutionary scope is in large part unforeseen, except by the imagination of the Utopians. Let me recall a wellknown example. If the Greek mathematicians had not applied themselves to the investigation of conic sections zealously and without the least suspicion that it might someday be useful, it would not have been possible centuries later to navigate far from shore. The first men to study the nature of electricity could not imagine that their experiments, carried on because of mere intellectual curiosity, would eventually lead to modern electrical technology without which we can scarcely conceive of contemporary life. Pure knowledge is valuable for its own sake, because the human spirit cannot resign itself to ignorance. But , in addition, it is the foundation for practical results that would not have been reached if this knowledge had not been sought disinterestedly. 48. The most important advance made by mankind e from ________. A. technical applications B. apparently useless information C. the natural sciences D. philosophy 49. In the paragraph that follows this passage, we may except the author to discuss ________. A. the value of technical research B. the value of pure research C. philosophy D. unforeseen discoveries 50. The title below that best expressed the ideas of this passage is ________. A. Technical Progress B. A Little Learning is a Dangerous Thing C. Man39。25,000 Kremer prize for the first such sustained flight when they had successfully flown a onemile figureeight course in McCready39。t wish to get into trouble, he will return the umbrella to No. 10 Broad Street. He is well known. This appeared in the paper, and on the following morning, the man was astonished when he opened the front door. In the doorway lay at least twelve umbrellas of all sizes and colors that had been thrown in, and his own was among the number. Many of them had notes fastened to them saying that they had been taken by mistake, and begging the loser mot to say anything about the matter. TEXT H First read the following questions. 54. What is the wingspan of the Gossamer Albatross? A. 33 kilograms B. 100 meters. C. 30 meters. D. Half of the wingspan of a DC9. 55. How much power did the Gossamer Albatross need to keep it flying? A. As much as a DC9. B. Less than one horsepower. C. Thee horsepower. D. Thirty horsepower. Now go through TEXT H quickly in order to answer 33 and 34 In June 1979, Bryan Allen, a biologist from California who is also a hanggliding enthusiast and an amateur racing cyclist, made history by pedaling across the English Channel in the Gossamer Albatross, a superlight, propellerdriven aircraft invented by Dr. Paul McCready. The Gossamer Albatross, a 33kilogram (72pound) aircraft with a polythenecovered fuselage and a wingspan of 30 meter (100 feet ), the same as that of a DC9 jet airliner, was driven mostly by conventional bicycle ponents. Allen sat on a bicycle saddle inside the transparent fuselage and pedaled a bicycle crank and chainwheel that turned a special urethane chain geared through two more chainwheels to a propeller mounted aft of the wing. Shortly after dawn that June day, the Albatross rolled down a harbored runway in Folkstone, England. Pedaling hard, Allen got the aircraft aloft and churned his way toward France. After almost three hours of pedaling to produce a constant output of about horsepower , he landed on a beach near Calais, the first person to fly a humanpowered craft across the Channel. Allen and an American team led by Dr. McCready were awarded the 39。 the chocolate itself then has to be unwrapped from its own piece of paper. But this insane amount of wrapping is not confined to luxuries. It is now being increasingly difficult to buy anything that is not done up in cellophane, polythene, or paper. The package itself is of no interest to the shopper, who usually throws it away immediately, unless wrapping accounts for much of the refuse put out by the average London household each week. So why is it done? Some of it, like the cellophane on meat, is necessary, but most of the rest is simply petitive selling. This is abused. Packaging is using up scarce energy and resources and messing up the environment. Little reach is being carried out on the costs of alternative types of packaging. Just how possible is it, for instance, for local authorities to salvage paper, pulp it, and recycle it as eggboxes? Would it be cheaper to plant another forest? Paper is the material most used for packaging 20 million paper bags are apparently used in Great Britain each day but very little is salvaged. A machine has been developed that pulps paper then processes it into packaging, . eggboxes and cartons. This could be easily adapted for local authorities use. It would mean that people would have to separate their refuse into paper and nonpaper, with a different dustbin for each. Paper is, in fact, probably the material that can be most easily recycled。s behavioral capacities. Later in life the changing outputs of some endocrine glands and the body39。m afraid it39。s Comet is probably the best known et. In 1973, Comet Kohoutek became the first et to be (20) by men in space. Astronauts in the Skylab space station (21) it and so provided much new information about ets. People used to believe the ing of a et would lead to a (22), such as a war or an epidemic. Halley39。s tail point away from the sun,. When a et (