单项选择题
A.Bell alarm to warn the user B.Lighted alarm signal to warn the user C.Alternate signal keying system D.View finder for each station
Loran-C uses the multiple pulse system because（）.A.Less...
单项选择题Loran-C uses the multiple pulse system because（）.
A.Less signal energy is necessary for receiver operation B.More signal energy is available at the receiver C.It significantly increases the peak power D.It increases the signal capacity
Loran-C is which type of system（）.A.Reflected electronB...
单项选择题Loran-C is which type of system（）.
A.Reflected electron B.Electrical radiation C.Quarterpoint electrical navigation D.Hyperbolic radio navigation
In using Loran-C，skywave reception gives greater range ...
单项选择题In using Loran-C，skywave reception gives greater range but is（）.
A.only accurate during daylight hours B.much less accurate C.only accurate at twilight D.more accurate than using ground waves
