GWD21

jeans2011

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 so the signals must be run through a piece of equipment called a regenerator before being transmitted farther. 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-line’s prospects?        E

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.
这题为什么选D呢？

pinkking

重新看看，应该选E

jiaoguitar

LZ觉得应该选D？

muslim

我认为应该选择D。E 说的是 are developing, 那这句话肯定没有告诉我们这个新技术已经developed, 如果成功，那可以对Light-line造成影响，但是如果不成功呢？

D则明确指出市场上就是由这样的技术，可以不用electric wire and optical.