A: The signal given
B: Giving the signal
C: The signal being given
D: The signal giving
举一反三
- ________, the train started. A: The signal given B: After the signal was given C: Given the signal D: A and B
- A ________may be given ____means of flags, lights, and guns. A: sign; by B: signal; in C: signal; by D: sign; in
- For a given signal constellation, the average probability of symbol error incurred in maximum likelihood signal detection over an AWGN channel is invariant to the _________________ of the signal constellation. A: compression B: translation C: expansion D: rotation
- 2. Railway signals can be divided into home signal, starting signal, distant signal, repeating signal and shunting signal.
- what is an analog signal? A: Analog signal is a continous values B: Analog signal is a discrete values C: Analog signal is sometimes continous,sometimes discrete
内容
- 0
a fixed signal that lets engineers know if a train can enter a block. A: ABS (automatic block system) B: lock C: lock signal
- 1
According to the meaning of stop signal, it is divided into absolute signal and （ ）. A: clea B: permissive signal C: estricting D: approach
- 2
Given the spectrum [img=21x22]18033774ad81d04.png[/img] of a continuous-time signal is shown below, then, the periodic signal signal [img=50x25]18033774b570388.png[/img][img=295x129]18033774bfda33c.png[/img] A: [img=142x20]18033774c806bc3.png[/img] B: [img=133x20]18033774d008a32.png[/img] C: [img=199x25]18033774d8e0526.png[/img] D: [img=138x21]18033774e1e1bd2.png[/img]
- 3
According to the meaning of stop signal, it is divided into absolute signal and _____.
- 4
Which of the following cell signaling molecules does the neurotransmitter belong to? ( ) A: Chemical signal B: Gas molecules C: Optical signal D: Electric signal