In the early 1950s the researchers who produced the first clad glass opt

游客2024-08-13 51

问题       In the early 1950s the researchers who produced the first clad glass optical fibers were not thinking of using them for communications.【C1】H __________, fiber optics was already a well-established commercial technology when the famous paper by Kao and Hockham, 【C2】__________(claim) the use of low-loss optical fibers for communication, appeared in 1966.The first low-loss silica fiber was described in 【C3】__________which appeared in October of 1970.The date of this publication is sometimes 【C4】__________(cite) as the beginning of the era of fiber communication.Although this development did receive 【C5】__________(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 【C6】wh__________ these fiber components could ever be produced economically enough, but the market potential was very significant.【C7】__________(consequence), research and development activity expanded rapidly, and a number of important issues were 【C8】 re__________ during the early 1970s.During the middle and late 1970s, the rate of progress towards marketable products accelerated as the emphasis 【C9】__________(shift) from research to engineering.Fibers with losses 【C10】app__________ the Rayleigh limit of 2 dB/km at a wavelength of 0.8μm were produced.
      By 1980 improvement in component performance, cost, and reliability led to major commitments on the part of telephone companies. [br] 【C4】

选项

答案 cited

解析句意为:这篇文章发表的日期经常被人们称为光纤通信时代的起始日。cite和日期之间是动宾关系,动作发出者是人们,故用cite的被动语态cited。

转载请注明原文地址:http://tihaiku.com/zcyy/3718333.html

相关试题推荐

随机试题

最新回复(0)

In the early 1950s the researchers who produced the first clad glass opt

ResearchersbelievetheymaybeabletouseDNAtouncoverthefateoftheL

ResearchersbelievetheymaybeabletouseDNAtouncoverthefateoftheL