The mode of control employed by an alarm circuit is a

A．two position control

B．single speed floating control

C．proportional speed floating control

D．reset control

[单选题]The control mode in which tile final control element is moved from one of two fixed positions to the other is known as______.A．dead band actionB．neutral zone actionC．rangeD．on-off action

[单选题]alarm的意义是（）。A .警告B .插入C .替换D .删除

[单选题]A．n alarm device inserted between the deaerating tank and the expansion tank can notify the on-watching crew that .A．the expansion tank is lack of waterB．the expansion tank is over flowingC．there is something wrong with the cooling systemD．there is s

[单选题]The alarm signal for engine room catching fire is a blast of random bell followed by____.A．two knocksB．three BlocksC．four knocksD．five knocks

[单选题]Engine protection by means of an alarm or shutdown control can be obtained with devices that are sensitive to （）.A . temperatureB . pressureC . engine speedD . all of the above

[单选题]A high temperature alarm or （） which will melt is used to guard against the explosion of compressor air pipelines.A . a flame trapB . a relief valveC . a fusible plugD . a bursting ca

[单选题][A] employed[B] appointed[C] interviewed[D] questioned

[主观题]H．ave you ever been employed?

[单选题]The pumps employed on board ship can be divided into two main categories ie（） pumps and centrifugal pumps.A . gearB . nonpositive displacementC . positive displacementD . rotary

[名词解释] SWLSS—MODE