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问题 选择题

分析、归纳、总结、运用是学习化学的有效方法。小明用“三”对初中所学知识进行归纳总结，其中错误的是    [ ]

A．常见的化石燃料有“三种”：煤、石油、天然气    

B．水污染主要来自“三个方面”：工业污染、农业污染、生活污染

C．一般燃烧的条件必须同时满足“三点”：可燃物、与氧气接触、温度达到着火点    

D．酸、碱、盐 溶液发生复分解反应时必须同时具备“三条 ”：生成物有水、气体和沉淀

答案

答案：D

填空题

During the 1980s, unemployment (失业人数) and underemployment (不充分就业) in some countries was so high as 90 per cent. Some countries did not 【B1】 enough food; basic needs in housing and clothing were not 【B2】 . Many of these countries looked 【B3】 the industrial processes of the developed nations for solution. 【B4】 , problems cannot always be solved by 【B5】 the industrialized nations. Industry in the developed nations is highly automated and very 【B6】 . It provides fewer jobs than labor-intensive industrial 【B7】 , and highly skilled workers are needed to 【B8】 and repair the equipment. These workers must be trained, 【B9】 many nations do not have the necessary training institutions. Thus, the 【B10】 of importing industry becomes higher. Students must be sent abroad to receive vocational and 【B11】 training. 【B12】 , just to begin training, the students must 【B13】 learn English, French, Germans, or Japanese. The students then spend many years abroad, and 【B14】 do not return home. All nations agree that science and technology should be shared. The point is: countries 【B15】 the industrial processes of the developed nations need to look carefully 【B16】 the costs, be cause ninny of these costs are 【B17】 Students from these nations should 【B18】 the problems of the industrialized countries closely. 【B19】 care, they will take home not the problems of science and technology, 【B20】 the benefits.

A．institutional

B．professional

C．universal

D．fundamental
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单项选择题

光纤信道OF-2000等级应支持的应用长度不应小于（）。

A.300m

B.500m

C.1000m

D.2000m
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