16: In recent years, networks of fiber-optic cable have been replacing electrical wire for transmitting telecommunications signals. Signals running through fiber-optic cables deteriorate, and so the signals must be run through a piece of equipment called a regenerator before being transmitted father. Light-Line is the leading manufacturer of signal regenerators. Therefore, Light-line is one of the companies that will most benefit if new long-distance fiber-optic telecommunications networks are constructed.
Which of the following, if true, casts the most doubt on the prediction about light-ling’s prospects?
A: Telecommunications signals sent along electrical wires can travel much farther than signals transmitted through fiber-optic before needing to be regenerated.
B: Expanding its production of regenerators will require Light-line to spend proportionately more on labor and materials.
C: The volume of signals that a fiber-optic cable can carry is several thousand times greater than the volume that can be carried by an electrical wire of similar size.
D: There are technologies that enable telecommunications signals to be transmitted without either wire or fiber-optic cable.
E: Several manufacturers are developing regenerator technologies that will allow signals to be transmitted many times farther than at present before requiring regeneration.
答案是E,我选的是D
E选项讲的是有几个制造商生产的regenerator能够信号比现在未regeneration之前的信号传播的远好几倍(比较拗口),我觉得这个是无关比较,文中并没有说L公司生产的regenerator不能使未regeneration之前的信号远几倍。是我理解错了吗?
而D选项也不大好,因为文中的结论是如果光纤投入使用,L会是获利最多的公司之一。
节后就要考试了,NN们帮忙。非常感谢。
应该是E。以前有讨论过。
注意结论是说,Therefore, Light-line is one of the companies that will most benefit if new long-distance fiber-optic telecommunications networks are constructed.
而D要削弱,则相当于说不需要建new long-distance fiber-optic telecommunications networks 。等于否定了假设性结论的前提,因而起不到削弱作用。
而E相当于可能要替代老的regeneration,所以紧扣题意。
D 是削弱前提,因此是错误的。
应该是E。以前有讨论过。
注意结论是说,Therefore, Light-line is one of the companies that will most benefit if new long-distance fiber-optic telecommunications networks are constructed.
而D要削弱,则相当于说不需要建new long-distance fiber-optic telecommunications networks 。等于否定了假设性结论的前提,因而起不到削弱作用。
而E相当于可能要替代老的regeneration,所以紧扣题意。
I don't agree with you. Even though the technology requires neither cable nor fiber-optic, you can't safely say the network won't be constructed without them. What about a new material, rather than cable or fiber-optic, that is used in the construction of the network? You never know, right?
觉得D虽错但是不是错在削弱前提,本题结论是:
光纤通信的伴随产品(就是那个什么genarator了)有商机,问削弱,而D没有"没有商机"的含义在里面,别种技术的存在不能减少某种技术的商机,除非说明别种技术特别有优势.
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