16. GWD31-16 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 wo the signals must be run through a piece of e3quiplent 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?
1) Telecommunications signals sent along electrical wires can travel much Farther than signals transmitted through fiber-optic before needing to be Regenerated. 2) Expanding its production of regenerators will require Light-line to spend Proportionately more on labor and materials. 3) 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. 4) There are technologies that enable telecommunications signals to be transmil Without either wire or fiber-optic cable 5) Several manufacturers are developing regenerator technologies that will allow To be transmitted many times farther than at present before requiring regeneration
我知道D 是混淆选项,但是又说不出来个所以然 希望大家帮忙!!!
|