When the angle of incidence is ......... the critical angle, the light beam bends along the interface.

Signals with a frequency below 2 MHz use ........... propagation.

Signals with a frequency between 2 MHz and 30 MHz use ______ propagation.

Signals with a frequency above 30 MHz use .......... propagation.

A parabolic dish antenna is an ............ antenna.

An .......... medium provides a physical conduit from one device to another.

............. cable consists of two insulated copper wires twisted together.

........... cable is used for voice and data communications.

............. consists of a central conductor and a shield.

............ cable can carry signals of higher frequency ranges than ............ cable.