GRE考试

【单选题】Electronic computer speeds are restricted not only by the speed of electrons in matter but also by the escalating density of interconnections necessary to connect the electronic gates on microchips.Electrical engineers and physicists have been developing and augmenting the technologies of analog and digital optical computing, in which the information is primarily carried by photons rather than by electrons. Optical computing could, in principle, generate much higher computer speeds, but one of the problems it has encountered lies in accuracy, for these devices have practical limits of 8 to 11 bits of accuracy in basic operations. Recent research has evinced that digital partitioning algorithms in tandem with error-correction codes, can substantially enhance the accuracy of optical computing operations. In the near term optical computers will most likely be hybrid optical/electronic systems that preprocess input data for computation and post-process output data via electronic circuits, but nevertheless, the prospect of all-optical computing remains highly attractive. According to the passage, which of the following is true concerning optical computers
A、Researchers have not yet discovered a means of transporting photons more efficiently.
B．Their primary limitation is the density of connections required between electronic microchip gates.
C．Their accuracy level is poor at 8 to 11 bits, but still superior to that Of electronic computers.
D．They invariably rely on electronic circuits to preprocess input data for computation.
E．Both analog and digital forms of optic computing are presently being developed by scientists.