A． vessel sounding a fog signal of one short，one prolonged，and one short blast is indicating that the vessel is ().

A．fishing

B．in distress

C．at anchor

D．not under command

[单选题]D．ense fog comes with bad visibility, fog signal bell must be kept ________at regulation intervalsA．to goB．goingC．goesD．go

[单选题]On a passenger vessel，the vessel’s name must appear on（）.A . ring life buoyB . lifeboatsC . lifeboat oarsD . All of the above

[单选题]Sounding带宽和系统带宽存在一定关系依据Sounding带宽，6个RB的系统带宽下发送()个RB的SRSA．1B．2C．4D．6

[单选题]英语SIGNAL指（）A .仪表B .开关C .按钮D .信号

[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]（）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

[单选题]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 encapsu

[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）