信息披露义务人可以向大型机构投资者先行披露有关投资信息。（）

A. Plenum

B. Fiber optic

C. Twisted pair

D. Coaxial

A. Fiber optic

B. Fast Ethernet

C. Coaxial

D. Thicknet

A、coaxial cable

B、telephone channel

C、universal Serial Bus

D、optical fiber

①Insert the tail fiber between subracks in the related interface, and bind the extra optical fiber by the yellow adhesive tap, fixing it on the cable immobility board inside the routing area to the right of the rack after routing the fiber through the routing slot in subrack.

②Insert the tail fiber between subracks in the related interface, and fix the extra optical fiber in the fiber-coiling box on the right of the subrack after routing it through the wire-routing slot. When there is very few internal fiber, you can also put the fiber-coiling box on the left of the rack.

③Arrange the optical fiber neatly, and put optical fiber tag on it.

④Decide the wiring path of the optical fiber and put tag on it according to the position of the interfaces on both ends of the optical fiber.

⑤Adopt a sequence of bottom up and from left to right when connecting the optical fiber on the ODU and the OMU board, and the fiber connection order on the OTU board should be the same. When there are multiple OTU subracks on the ODU or the OMU board, first connect the optical fiber between subracks first, and then connect the optical fiber inside the subrack.

A.③-⑤-②-①-④

B.③-⑤-①-②-④

C.④-⑤-②-①-③

D.④-⑤-①-②-③

A. optical technology for transmitting up to 32 channels over multiple fiber strands

B. optical technology for transmitting up to 16 channels over multiple fiber strands

C. a WDM system that is compatible with EDFA technology

D. a technology for transmitting more closely packed optical signals using more sophisticated transceiver designs than CWDM .

Translate into Chinese. 1.Dense WDM however is another thing. Dense WDM refers to the close spacing of channels. Sadly, "dense" is a qualitative measure and just what dense means is largely in the mind of a particular individual. To some, a series of WDM channels spaced at 3.6 nm apart qualifies for the description. Others use the term to distinguish systems where the wavelength spacing is1nm per channel or less. 2.In 1998 the "happening” Wavelength Division area in optical communications was Multiplexing (WDM). This is the ability to send many (perhaps up to 1000) independent optical channels on a single fiber. 3.If a short pulse of light from a source such as a laser or an LED is sent down a narrow fiber, it will be changed (degraded) by its passage down the fiber. It will emerge (depending on the distance) much weaker, lengthened in time ("smeared our"), and distorted in other ways. 4.In the wide area environment a large coaxial cable system can easily involve a cable of several inches in diameter and weighing many pounds per foot. 5.It is possible to tap fiber optical cable. But it is very difficult to do and the additional loss caused by the tap is relatively easy to detect. There is an interruption to service while the tap is inserted and this can alert operational staff to the situation. In addition, there are fewer access points where an intruder can gain the kind of access to a fiber cable necessary to insert a tap.

Fiber optic cables can carry hundreds of telephone conversations （）．

A．homogeneously

B．spontaneously

C．simultaneously

D．ingeniously

Fiber optic cables can carry hundreds of telephone conversations （）．

A．homogeneously

B．spontaneously

C．simultaneously

D．ingeniously