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。
就要考试了，NN们帮忙。非常感谢。 | 
