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In the early 1950s the researchers who produced the first clad glass optical fibers were not thinking of using them for communications.【46】H______, fiber optics was already a well-established commercial technology when the famous paper by Kao and Hockham,【47】______ (claim) the use of low-loss optical fibers for communication, appeared in 1966. The first low-loss silica fiber was described in【48】______which appeared in October of 1970. The date of this publication is sometimes【49】______(cite) as the beginning of the era of fiber communication. Although this development did receive【50】______ (consider) attention in the research community at the time, it was far from inevitable that a major industry would evolve. The technological barriers appeared formidable because there were serious doubts as to【51】 wh______these fiber components could ever be produced economically enough, but the market potential was very significant.【52】______(consequence) , research and development activity expanded rapidly, and a number of important issues were【53】re______during the early 1970s. During the middle and late 1970s, the rate of progress towards marketable products accelerated as the emphasis【54】______(shift) from research to engineering. Fibers with losses【55】app______the Rayleigh limit of 2 dB/km at a wavelength of 0. 8 μm were produced. By 1980 improvement in component performance, cost, and reliability led to major commitments on the part of telephone companies. (16)
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【单选题】下列不属于流通加工作用的是()
A.
提高原材料利用率
B.
进行初级加工,方便使用
C.
提高加工效率及设备利用率
D.
对安全性要求高
【多选题】下列属于流通加工的作用的选项是( )
A.
弥补生产加工的不足
B.
方便用户
C.
提高加工效率及设备利用率
D.
提高原材料利用率
【多选题】下列属于流通加工的作用的选项是( )。
A.
弥补生产加工的不足
B.
方便配送
C.
提高劳动生产率
D.
提高物流生产率
【单选题】( )技能对于高层管理最重要,对于中层管理较重要,对于基层管理较不重要。
A.
技术技能
B.
人际技能
C.
概念技能
D.
沟通技能
【多选题】下列属于流通加工的作用的选项是
A.
提高原材料利用率
B.
进行初级加工、方便用户
C.
提高加工效率及设备利用率
D.
降低劳动生产率
【单选题】( )技能对于高层管理最重要,对于中层管理较重要,对于基层管理较不重要。
A.
工艺技能
B.
概念技能
C.
人际技能
D.
技术技能
【单选题】对于高层管理最重要,对于中层管理较重要,对于基层管理不重要的技能是:
A.
技术技能
B.
人际技能
C.
概念技能
D.
领导技能
【简答题】Guided Writing . Directions: Write an English composition in 120-150 words according to the instruction below. 上星期 的班会课上你们进行了一场英语辩论赛。辩题是“Sport is really good for us” 你班的张,李,赵同 学发表了以下观点:请你仔细阅读下列3位学生的观点...
【单选题】下面能把回转运动变为往复运动的机构是_____。 A.凸轮机构 B.链传动机构 C.蜗轮蜗杆机构 D.带传动机构
A.
选A
B.
选B
C.
选C
D.
选D
【单选题】某厂 1993年生产了一种治疗腰肌劳损的频谱治疗仪投放市场, 消费者甲购买了一部, 用 后腰肌劳损大大减轻, 但却患上了偏头疼症, 甲询问了这种治疗仪的其他用户, 很多人都有 类似反应。甲向某厂要求索赔。某厂对此十分重视,专门找专家作了鉴定,结论是;目前科 学技术无法断定治疗仪与偏头疼之间的关系。以下哪种观点正确?
A.
.本着公平原则,某厂应予适当赔偿
B.
.因出现不良反应的用户众多,应将争议搁置,待科技发展到能够作出明确结论时再处理
C.
.该治疗仪的功能是治疗腰肌劳损,该功能完全具备,至于其他副作用是治疗中不可避免
D.
该厂可不负责任
E.
.由于治疗仪投入流通时的科学技术水平不能发现缺陷的存在,某厂不能承担赔偿责任
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