Communication satellites relay ( ) zuoy
A. voice
B. video
C. repeater
D. data signals
The satellite must have ( )
A. a receiver
B. a receiver antenna
C. a transmitter and a transmit antenna
D. electrical power
Modern communications satellites use a variety of orbits, including ( ).
A. geostationary orbits
B. Molniya orbits
C. elliptical orbits
D. low (Polar and non-polar) earth orbits
Satellites communication has many advantages including ( ).
A. less costly for transmission over extremely long distances
B. a communication signal can be sent to any number of reception points simultaneously
C. extremely flexible
D. the sending and receiving points can be changed
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