In(66)the strength of the carrier signal is varied to represent binary 1 or 0.(67)is a system that can map a name to an address and conversely an address to al name.(68)is a three-way handshaking authentication protocol that it's packets are encapsulated in the point-to-point protocol.(69)is an approach that enables an ATM switch to behave like a LAN switch.(70)is an guided media which is made of glass or plastic and transmits signals in the form. of light.

A．ASK

B．PSK

C．FSK

D．FDM

[单选题]In the strength of the carrier signal is varied to represent binary 1 or 0.(72) is a system that can map a name to an address and conversely an address to an name.(73) is a three-way handshaking authentication protocol that it's packets are encapsul

[单选题] (71) In the strength of the carrier signal is varied to represent binary 1 or 0．(72) is a system that can map a name to an address and conversely an address to an name．(73) is a three-way handshaking authentication protocol that it's packets are en

[单选题]The strength of a deck will be increased by adding（）.A . camberB . deck beam bracketsC . hatch beamsD . sheer

[单选题]英语SIGNAL指（）A .仪表B .开关C .按钮D .信号

[问答题] 载体（carrier）

[名词解释] carrier载波

[单选题]（）is the most visible signal of distress from a lifeboat at sea in the daytime.A . Smoke signalB . Flash signalC . Fire signalD . Radio emergency transmissio

[名词解释] Signal loss信号损耗

[名词解释] 信号相位（Signal Phase）

[名词解释] 信号斑（signal patch）