323、Computer hard drives hold an enonnous amount of data or information.It is very important that all of the data is well.

298、Computer networks also use flexible glass fibers to transmit data.Known as an optical fiber, the medium uses light to transport data, The miniature glass fiber is encased in a plastic jacket which allows the fiber to bend without breaking.A transmitter at one end of a fiber uses a light emitting diode ( ) or a laser to send pulses of light down the fiber.A receiver at the other end uses a light sensitive transistor to detect the pulses. Optical fibers have four main advantages over wires.First, because they use light, optical fibers neither cause electrical interference in other cables nor are they susceptible to electrical interference.Second, because glass fibers cab be manufactured to reflect most of the light inward, a fiber can carry a pulse of light much farther than a copper wire can carry a signal.Third, because light can encode more information than electrical signals, an optical fiber can carry more information than a wire.Fourth, unlike electricity, which always requires a pair of wires connected into a complete circuit, light can travel from one computer to another over a single fiber. Despite their advantages, optical fibers do have some disadvantages.First, installing a fiber requires special equipment that polishes the ends to allow light to pass through.Second, if a fiber breaks inside the plastic jacket ( ), finding the location of the problem is difficult.Third, repairing a broken fiber is difficult because special equipment is needed to join two fibers so that light can pass through the joint.(2)、How many advantages of optical fibers have been mentioned in this text?

298、Computer networks also use flexible glass fibers to transmit data.Known as an optical fiber, the medium uses light to transport data, The miniature glass fiber is encased in a plastic jacket which allows the fiber to bend without breaking.A transmitter at one end of a fiber uses a light emitting diode ( ) or a laser to send pulses of light down the fiber.A receiver at the other end uses a light sensitive transistor to detect the pulses. Optical fibers have four main advantages over wires.First, because they use light, optical fibers neither cause electrical interference in other cables nor are they susceptible to electrical interference.Second, because glass fibers cab be manufactured to reflect most of the light inward, a fiber can carry a pulse of light much farther than a copper wire can carry a signal.Third, because light can encode more information than electrical signals, an optical fiber can carry more information than a wire.Fourth, unlike electricity, which always requires a pair of wires connected into a complete circuit, light can travel from one computer to another over a single fiber. Despite their advantages, optical fibers do have some disadvantages.First, installing a fiber requires special equipment that polishes the ends to allow light to pass through.Second, if a fiber breaks inside the plastic jacket ( ), finding the location of the problem is difficult.Third, repairing a broken fiber is difficult because special equipment is needed to join two fibers so that light can pass through the joint.(1)、 What is the material of the optical fiber?

297、In a star-bus topology, several star topology networks are bus connection.

296、The motherboard of a typical desktop a large printed circuit board.

295、The channel realizes the unified management of the peripheral equipment and the data transfer between the peripheral equipment and the main memory.

294、This is particularly true in cases are a large number of choices, most of which are “good”.

293、In a greedy algorithm, at each decision point the choice that has the immediate cost is selected.

292、5.Flash memory blocks have to be explicitly erased they can be written to.

291、4.To make sense of this potentially situation, structured programming was created.

290、Disk is a memory that uses magnetic recording technology to data.