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安全网的冲击性能试验，是将密日式安全网水平放置，四边拉紧固定。在网中心上方1.5m处，有一个100kg重的砂袋自由落下，网边撕裂的长度小于( )，即为合格。
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In the nineteenth century Charles Dickens, the English novelist, wrote excitedly (1) a stage-coach, pulled along by a team of horses, that could (2) more than twenty miles of road within sixty minutes. To us in the twentieth century in (3) man is able to move and to communicate with such rapidity, the (4) of the stage-coach seems no speed at all. Aeroplanes fly many hundreds of miles in an hour; express trains (5) four times the speed of the stage-coach; and even without (6) we can, by wireless or telegraph, communicate within seconds with people on (7) side of the’ globe. The (8) of these increased speeds are numerous. Business (9) say, from Europe to America or to the Far East can save much time. (10) a journey that would once have taken weeks, it (11) now, by air, only twenty-four hours. Fruit, vegetables and other goods that would decay (12) a long, slow journey can now be safely sent to far-distant places. Members of one family (13) each other by vast distances can have conversations with each other by telephone (14)if they were all sitting in the same room.Not ail the effects of speed, however, are (15) People who are in the habit of using a motor car (16) they want to move half a mile become physically lazy and lose the (17) of enjoying a vigorous walk. Those who travel through a country at eighty miles a hour do not see much of the life of that country, of its people and animals and plants, as they flash (18) They become so anxious about moving quickly from one place to another that they are (19) able to relax and enjoy a (20) journey. Read the following text. Choose the best word(s) for each numbered blank and mark A,B,C or D on ANSWER SHEET Ⅰ.9（）
In the nineteenth century Charles Dickens, the English novelist, wrote excitedly (1) a stage-coach, pulled along by a team of horses, that could (2) more than twenty miles of road within sixty minutes. To us in the twentieth century in (3) man is able to move and to communicate with such rapidity, the (4) of the stage-coach seems no speed at all. Aeroplanes fly many hundreds of miles in an hour; express trains (5) four times the speed of the stage-coach; and even without (6) we can, by wireless or telegraph, communicate within seconds with people on (7) side of the’ globe. The (8) of these increased speeds are numerous. Business (9) say, from Europe to America or to the Far East can save much time. (10) a journey that would once have taken weeks, it (11) now, by air, only twenty-four hours. Fruit, vegetables and other goods that would decay (12) a long, slow journey can now be safely sent to far-distant places. Members of one family (13) each other by vast distances can have conversations with each other by telephone (14)if they were all sitting in the same room.Not ail the effects of speed, however, are (15) People who are in the habit of using a motor car (16) they want to move half a mile become physically lazy and lose the (17) of enjoying a vigorous walk. Those who travel through a country at eighty miles a hour do not see much of the life of that country, of its people and animals and plants, as they flash (18) They become so anxious about moving quickly from one place to another that they are (19) able to relax and enjoy a (20) journey. Read the following text. Choose the best word(s) for each numbered blank and mark A,B,C or D on ANSWER SHEET Ⅰ.7（）
Text 2There was great public interest when a big hole mysteriously appeared in the middle of a field. Army mechanics and engineers were called in to explain how it had got there. They orrered various explanations but were not at all sure how the hole had’been caused. It was thought that a large shell which must have lain buried under the ground for many years had suddenly exploded, but it was not possible to prove this.A “simple", but highly improbable, explanation was offered by a man who claims to be especially well-informed about "flying saucers —the strange objects which are round in shape and are said to visit the earth occasionally from outer space. The man’s explanation may have been nonsense, but at least it was imaginative. At any rate, it was far more interesting than the one given by the army.After examing the ground carefully, the man claimed to have seen special marks on the soil quite near the hole. These, he said, could only have been caused by a flying saucer. Moreover, the leaves on some bushes nearby had turned yellow because of a strange hot gas which had come from the saucer just before it landed. Even a small tree some way off appeared to have been burnt slightly. A small piece of metal found in the hole itself provided further proof that a strange object had been there. According to the man, it was quite clear that people from another world had been circling the earth trying to pick up information, when something had gone wrong. Because of this they had been forced to land in a field so that the damage could be repaired. The hole had been caused when the saucer struck the earth, while the strange marks nearby were made when it took off again. This, said the man, was the simplest explanation of how the hole had appeared. Judging from the interest the public took in the matter, there must be quite a few people who secretly believe or hope that this "simple" explanation is the true one. In the man's opinion something happened to the flying saucer when（）
Text 3The farm is a major marketplace for millions of tons of synthetic fertilizers and pesticides (杀虫剂),and advanced machinery and the fuel required to run it. The modem superfarm, large and highly capitalized, is resource dependent compared with the diversified small farms that were once dominant. On diversified farms, major energy needs may be supplied by resident humans and animals. Soil fertility may be maintained by alternating cash crops and restorative crops, and also by returning animal manure (肥料) to the soil. This farming model of relatively self- sufficient agriculture, and the way of life associated with it, are still economically viable (可行 ), as demonstrated by prosperous Amish farmers and other practitioners of "alternative" agriculture. Particularly relevant to today’s mainstream agriculture are the energy-saving practices on large "organic" farms, which are thoroughly mechanized but which minimize the use of pesticides and synthetic fertilizers.By comparison, mainstream American agriculture has until lately been careless in its use of energy, water, and land. When fossil energy was cheap, applications of fertilizers and pesticides paid large dividends, so farmers were encouraged to use these products. Soon most farmers used too much fertilizer and pesticide. Farmers in dry regions enjoyed an era of cheap water, obtained from publicly subsidized irrigation systems or from pumping groundwater using, inexpensive energy. The soil too was expendable as demand grew f6r U.S. agricultural products.The period of extraordinary profligacy in the use of soil, water, and fossil fuels may well be at an end. The new structure of large farms is quite sensitive to cost factors. These adaptive farms, whose development was assisted by public tax, subsidy, and research policies, have access to capital, technologies, and management skills, enabling them to switch relatively quickly to resource-conserving practices -- for example, to a low-tillage system that requires less fuel, that shepherds soil moisture, and that may reduce soil erosion (侵蚀). It seems likely that federal programs that have enlarged our farms, therefore, have had a further result of creating the potential for a more conserving agriculture. With respect to energy use, for example, energy costs per unit of output are lower for large farms, mainly because these farms quickly economized on energy as costs rose. In the future, according to one authoritative assessment, "agricultural production is likely to use capital and land more intensively but energy, fertilizer and labor less intensively." The word "profligacy" ( line 1, parA．3 ) most probably means（）
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