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就目前计算设备的计算能力而言，数据加密标准DES不能抵抗对密钥的穷举搜索攻击，其原因是（）。
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用来辅助软件开发、运行、维护、管理、支持等过程中的活动的软件称为软件开发工具，通常也称为 (63) 工具。使用软件开发工具有助于提高软件的开发、维护和管理的效率。集成型软件开发环境通常由工具集和环境集成机制组成。这种环境应具有 (64) 。环境集成机制有数据集成机制、控制集成机制和界面集成机制。数据集成机制为环境中的工具提供统一的 (65) ；控制集成机制为 (66) 提供支持。界面集成机制使得环境中的所有工具具有 (67) 。 65（）
阅读下面这篇短文，短文后有2项测试任务：(1)第23～26题要求从所给的6个选项中为规定段每段选择1个正确的小标题；(2)第27～30题要求从所给的6个选项中选择4个正确选项，分别完成每个句子。 There are now over 700 million motor vehicles in the world-and the number is rising by more than 40 million each year. The average distance driven by car users is growing too-from 8 km a day per person in western Europe in 1965 to 25 km a day in 1995. This dependence on motor vehicles had given rise to major problems, including environmental pollution, depletion of oil resources, traffic congestion and safety.2. Until a hundred years ago, most journeys were in the 20 km range, the distance conveniently accessible by horse. Heavy freight could only be carried by water or rail. The invention of the motor vehicle brought personal mobility to the masses and made rapid freight delivery possible over a much wider area. Today 90 per cent of inland freight in the United Kingdom is carried by road. Clearly the world cannot revert to the horse-drawn wagon. Can it avoid being locked into congested and pollution ways of transporting people and goods3. In Europe most cities are still designed for the old modes of transport. Adaptation to the motor car has involved adding ring roads, one-way systems and parking lots. In the United States, more land is assigned to car use than to housing. Urban sprawl means that life without a car is nest to impossible. Mass use of motor vehicles has also killed or injured millions of people. Other social effects have been blamed on the car such as alienation and aggressive human behaviour.4. A 1993 study by the European Federation for Transport and Environment found that car transport is seven times as costly as rail travel in terms of he external social costs it entails such as congestion, accidents, pollution, loss of cropland and natural habitats, depletion of oil resources, and so on. Yet cars easily surpass trains or buses as a flexible and convenient mode of personal transport. It is unrealistic to expect people to give up private cars in favour of mass transit.5. Technical solutions can reduce the pollution problem and increase the fuel efficiency of engines. But fuel consumption and exhaust emissions depend on which cars are preferred by customers and how they are driven. Many people buy larger cars than they need for daily purposes or waste fuel by driving aggressively. Besides, global car use is increasing at a faster rate than the improvement in emissions and fuel efficiency which technology is now making possible.6. A more likely scenario seems to be a combination of mass transit systems for travel into and around cities. With small "low emission" cars for urban use and larger hybrid or lean burn cars for use elsewhere. Electronically tolled highways might be used to ensure that drivers pay charges geared to actual road use. Better integration of transport systems is also highly desirable-and made more feasible by modern computers. But these are solutions for countries which can afford them. In most developing countries, old cars and old technologies continue to predominate. Paragraph 3 ______
用来辅助软件开发、运行、维护、管理、支持等过程中的活动的软件称为软件开发工具，通常也称为 (63) 工具。使用软件开发工具有助于提高软件的开发、维护和管理的效率。集成型软件开发环境通常由工具集和环境集成机制组成。这种环境应具有 (64) 。环境集成机制有数据集成机制、控制集成机制和界面集成机制。数据集成机制为环境中的工具提供统一的 (65) ；控制集成机制为 (66) 提供支持。界面集成机制使得环境中的所有工具具有 (67) 。 64（）
第三篇 If the salinity(含盐量) of ocean waters is analyzed, it is round to vary only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation—conversion of liquid water to water vapor. In this manner, the salinity is increased, since the sales stay behind. If this is carried to the extreme, of course, white crystals of salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained. The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff. Normally, in tropical regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas. A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water. In the Weddell Sea, off Antarctica, the densest water in the oceans is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the oceans of the world. Which of the following statements about the salinity of a body of water can best be inferred from the passage
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