signal
举一反三
- 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
- ________, the train started. A: The signal given B: After the signal was given C: Given the signal D: A and B
- According to the meaning of stop signal, it is divided into absolute signal and _____.
- According to the meaning of stop signal, it is divided into absolute signal and （ ）. A: clea B: permissive signal C: estricting D: approach